Present COVID vaccines may not be effective during the 4th COVID wave in India.
As evidence mounts that new strains of the SARS-CoV-2 COVID can defy immunity engendered by vaccines or past infections, scientists are considering reworking the vaccines now in use worldwide.
Researchers are currently arguing whether the new variants will reduce the efficacy of COVID-19 vaccinations from the first generation. However, several vaccine producers are pushing ahead with plans to upgrade their vaccines to better target new variations like those found in South Africa and Brazil. These lineages have mutations that appear to reduce the effectiveness of infection-fighting antibodies. Researchers are also examining whether coronavirus vaccinations, like influenza vaccines, need to be updated regularly.
According to Mani Foroohar, a biotechnology analyst at Boston-based investment bank SVB Leerink, the best and most immediate strategy to tackle the threat of emerging variations is to vaccinate as many individuals as possible with current vaccines swiftly: “We need to get vaccines in our hands and suffocate this virus before it resurfaces.”
However, Foroohar and others believe that a slew of new vaccinations will emerge in the future to combat the COVID-19 variations front on. Nature looks at the unanswered concerns surrounding the world’s coronavirus vaccines.
According to preliminary assessments, the fourth wave of the Covid-19 will begin in June-July and extend till September, according to Karnataka Health Minister K. Sudhakar. He continued, “Karnataka is prepared to confront it.”
He stated that there is no cause to be concerned about. The new XE form of Covid-19 is prevalent in eight nations, and people arriving from those countries are examined. In response to a question, he stated that the mask is still required and there will be no relaxation, but that the 4th wave is unimportant. There will be 5,000 children aged 6 to 12 who are not yet eligible for vaccination.
Sudhakar said that many vaccines previously administered to children arrived in India decades after they were available elsewhere when discussing India’s vaccination progress.
“I don’t want to bring politics into this collective pandemic struggle, but people should be aware of it. Vaccines arrived significantly later in India than in the rest of the globe throughout the last 70 years while other parties controlled.”
What are the opinions of specialists on the fourth wave?
There is no clear consensus in India on when or how the fourth wave of Covid-19 will play out. Although Omicron was far more contagious than prior variations, the peak number of positive cases during the third wave was not significantly higher than the second wave. This could be attributable to several variables, including increasing immunization and decreasing the number of tested persons (since Omicron may only show mild symptoms in most people).
However, other scientists believe that simply because the Omicron type was fortunate, we cannot rely on luck in the future. Future coronavirus variants from the Alpha or Delta lineages may evolve, resulting in a deadlier and more contagious variety. If this happens, this strain has a good chance of becoming the dominant one and displacing Omicron.
Others believe it is hard to predict the effect because there are so many variables to consider. Before we can evaluate how a novel variant will spread and affect the population, we need to look at two essential factors: transmission rate and fatality rate.
Vaccines’ Importance in the Fourth Wave
More and more evidence is accumulating that immunizations (whether first-dose, second-dose, or booster) can reduce the rate of fatalities and hospitalization in general populations. It is still our most crucial defence tactic on a big scale and our best prospect of surviving the pandemic.
Almost no one was vaccinated in India during the first and second waves. The country was still implementing an extensive vaccination campaign during the third wave to protect its massive population. 70 percent of India’s population had received at least one therapy as of the first several months of 2022, with around 58 percent receiving at least two doses. These variables could influence how the fourth wave develops. It must also be considered by statisticians and epidemiologists when predicting the shape of a future fourth wave.
Vaccinations and booster shots might or might not help slow the spread of a new variant, but only time will tell.
Is there going to be the fourth wave?
While a fourth wave is unlikely, new coronavirus varieties are unavoidable. According to the WHO and numerous medical authorities around the world, Omicron is not the last variety, nor will it be the most contagious. Viruses are naturally evolving organisms, and each time they spread, a new variant may emerge. However, not all variants evolve to become more lethal, and not all variants become more contagious.
There’s a chance that a more lethal form will emerge, but it’s also possible that it won’t. Regardless, we must be extra alert and utilize whatever tools and processes we have at our disposal to limit the virus’s spread.
According to some analysts, the fourth wave (if it comes) might start as early as June 2022 and peak in August. It’s difficult to say whether this forecast will come true until we learn more about the new variety.
Will we require COVID-19 vaccines that have been updated?
“I believe it is beginning to appear that way,” says Kanta Subbarao, a virologist at Melbourne’s Peter Doherty Institute for Infection and Immunity.
Laboratories worldwide are scrambling to figure out what harm new coronavirus strains pose to vaccines. However, the first findings from these investigations are contradictory and incomplete. One of the more concerning variants is 501Y.V2 (also known as variant B.1.351), discovered in late 2020 in South Africa. According to lab tests, it carries mutations that reduce the potency of virus-inactivating ‘neutralizing antibodies’ produced by people who received either the Pfizer or Moderna RNA vaccines.
According to Subbarao, whether these alterations are sufficient to reduce the vaccinations’ effectiveness is unclear. “We don’t know how many antibodies you need, so that’s the million-dollar question.” Other immune responses elicited by vaccines may help to guard against variant effects.
However, on January 28, biotech firm Novavax disclosed data from clinical trials suggesting that its experimental vaccine, which was meant to battle the original virus, was roughly 85% effective against a variation detected in the United Kingdom but less than 50% effective against 501Y.V2. According to researchers, this decrease is worrying since it suggests that 501Y.V2 and other variants like it can reduce vaccine effectiveness significantly.
“I believe it is unavoidable that vaccinations be updated to retain peak efficacy.” The only question is when and how often,” says Paul Bieniasz, a virologist at New York City’s Rockefeller University who co-led one neutralizing-antibody experiment.
When should vaccines be updated, and how should we decide?
Scientists, health regulators, and vaccine manufacturers are beginning to work out the details. Researchers only understand how different mutations affect vaccine responses and how modifications propagate due to evolutionary processes. “I wouldn’t update them right now,” Bieniasz says.
According to Subbarao, who runs the World Health Organization Collaborating Centre for Reference and Research on Influenza in Melbourne, one model that COVID-19 vaccine updates could follow is seasonal flu vaccines. Her centre, like others, keeps an eye on new flu strains for genetic changes that could affect vaccine effectiveness. Researchers employ ferret and human antibody research to predict whether a new flu strain is likely to resist a previous season’s vaccine, necessitating a vaccine update. According to Subbarao, these reviews are done annually for each hemisphere’s flu season, and changes are made only when a vaccine-evading strain becomes widespread. “We wouldn’t update the vaccine for the entire globe if it’s localized to one region, one country.”
In general, the threshold for updating flu vaccinations is similar to the point for changes in neutralizing-antibody reactions connected to the 501Y.V2 variation, according to researchers. However, it is unclear how these changes and the geographic distribution of distinct variations and mutations may affect COVID-19 vaccination updates. “Those talks are just getting started,” Subbarao says. “We can’t be on the lookout for every new variety.”
What method will be used to update the vaccines?
Another unanswered question. Some COVID-19 vaccines, such as those produced by Moderna, Pfizer, and AstraZeneca, tell cells to make the virus spike protein, the immune system’s primary target for coronaviruses. Spike mutations in 501Y.V2 and other variants change the areas targeted by neutralizing antibodies.
One option is to replace outdated forms of the spike protein in vaccines — primarily based on the virus that was first discovered in Wuhan, China — with an updated molecule containing the unique amino-acid modifications that thwart antibody reactions. However, researchers must first find whether such changes have side effects that affect how the immune system responds to the vaccination. Another option is to combine the new and old forms of the spike protein in a single immunization, which scientists refer to as a multivalent vaccine.
Moderna has begun upgrading its mRNA vaccine to match 501Y.V2 spike mutations. In a call with investors on January 25, Tal Zaks, Moderna’s chief scientific officer, said the biotech business, based in Cambridge, Massachusetts, plans to test the efficacy of the third dose of its original coronavirus vaccine and is looking into the feasibility of a multivalent vaccine. According to Subbarao, researchers must investigate how animals, and most likely humans, react to any future vaccine update before deciding on a course of action. “It won’t be as easy as changing an amino acid position and saying, ‘OK, we got it.'”
What methods will be used to test and approve vaccines?
Before authorities approved the use of the currently available COVID-19 vaccines, vaccine makers conducted phase III trials involving tens of thousands of people. But, as immunologist Drew Weissman of the University of Pennsylvania in Philadelphia points out, such testing for a redesigned vaccine would be slow and difficult now that the first-generation vaccines have been widely deployed: “I don’t see how a variant could be tested in a phase III trial.”
It’s unclear how much clinical evidence is required before a COVID-19 vaccine update could be approved. In most cases, new seasonal flu vaccinations do not need further studies. On the other hand, regulators lack the confidence that comes with decades of expertise and clinical data with COVID-19 vaccinations. “They may say, ‘It’s a brand new vaccine. Let’s do a couple of clinical trials,'” Weissman speculated.
The number and duration of such trials may be determined by whether researchers can identify “correlates of protection,” which are measurable aspects of an immune response, such as a certain quantity of neutralizing antibodies, that can serve as a marker for COVID-19 protection. Researchers would no longer need to wait for trial participants to become infected with coronavirus to determine whether the vaccinations are effective; instead, they could test immune responses after each dosage using such markers.
According to Paul Offit, a vaccination researcher at the Children’s Hospital of Philadelphia in Pennsylvania, “there is no certainty that a robust correlate will emerge.” Despite the lack of a definitive connection, researchers may be able to show that their new vaccination produces antibody levels comparable to those produced by first-generation vaccines.
Moderna expects to be able to move forward with its vaccine against the 501Y.V2 variation based on clinical trials involving hundreds, rather than thousands, of people. From the time the business produces the new vaccine to when it submits results from its practices to authorities, Foroohar estimates it will take around five months.
The number and duration of such trials may be determined by whether researchers can identify “correlates of protection,” which are measurable aspects of an immune response, such as a certain quantity of neutralizing antibodies, that can serve as a marker for COVID-19 protection. Researchers would no longer need to wait for trial participants to become infected with coronavirus to determine whether the vaccinations are effective; instead, they could test immune responses after each dosage using such markers.
According to Paul Offit, a vaccination researcher at the Children’s Hospital of Philadelphia in Pennsylvania, “there is no certainty that a robust correlate will emerge.” Despite the lack of a definitive connection, researchers may be able to show that their new vaccination produces antibody levels comparable to those produced by first-generation vaccines.
Moderna expects to be able to move forward with its vaccine against the 501Y.V2 variation based on clinical trials involving hundreds, rather than thousands, of people. From the time the business produces the new vaccine to the time it submits results from its problems to authorities, Foroohar estimates it will take around five months.
How will people react to updated vaccines if they have already been inoculated?
Researchers are still unsure how a person who has been fully vaccinated with a first-generation COVID-19 vaccine will react to a new variation. Immunologists have long noticed that people’s immune responses to the first variant of a virus they encounter are more robust than those to subsequent variants. This pattern could indicate that updated vaccines may elicit more subdued immune responses than a first-generation vaccine. “The concern is that boosting someone with a variant will not result in a new reaction to that variant,” Weissman explains. “It’ll merely amplify the previous response.”
However, according to Weissman, there is some evidence that RNA vaccines may not be affected by this tendency. Some RNA vaccines elicit unusually sophisticated immune responses, including antibodies that target areas of viral proteins that are rarely found in reactions to other types of vaccinations for unknown reasons. According to Weissman, this could suggest that RNA vaccines will be better equipped to target the modifications contained in a variant.
Offit also points out that a variant-specific response may not be required: even if an updated vaccine primarily improves the response to an older coronavirus vaccine, that may be sufficient to ward off variants, he adds.
Vaccines for COVID-19 and novel viral variations
Viruses are constantly evolving, and new viruses, known as variations, emerge. In the United States and other parts of the world, new versions of the virus that causes COVID-19 are proliferating. COVID-19 vaccinations used in the United States have been shown to protect against severe disease, hospitalization, and death from several identified variations of concern. Still, they may not be as effective in avoiding asymptomatic infection. The CDC will continue to track efficacy to see if polymorphisms affect COVID-19 vaccinations’ effectiveness in real-world situations.
How the CDC evaluates the effectiveness of the COVID-19 vaccination
The CDC investigates vaccine effectiveness and safety using a variety of ways. The FDA and vaccine makers conduct research on vaccine efficacy, measured in randomized controlled trials, before releasing vaccines to the public. After vaccinations are made available to the public, the CDC conducts observational studies, often known as vaccine effectiveness studies, to see how they function in real-world situations. CDC works on a variety of studies to determine COVID-19 vaccine effectiveness in real-world problems and research conducted by vaccine makers, other government agencies, and university investigators. Many of these studies have been published in academic journals like the Morbidity and Mortality Weekly Report (MMWR).
Why does the CDC keep track of vaccine effectiveness?
Vaccine efficacy studies assist the CDC in determining concerns such as vaccine effectiveness diminishing over time after immunization and the need for—or advantages offered by—vaccine boosters in various age groups and special populations (adults ages 65 and older, people with underlying health conditions, and healthcare workers).
Examining how vaccinations function in the actual world allows us to:
- As needed, make changes to immunization recommendations, such as booster doses.
- Vaccine policy and distribution should be informed.
- Assist with the development of vaccine technologies in the future
In the Delta wave, India’s Covaxin provides less protection.
According to a real-world analysis, Covaxin, one of the most important coronavirus vaccines used in India, only provides 50% protection against symptomatic Covid-19. This demonstrates that the shot is less effective than previously assumed.
Researchers at the All India Institute of Medical Sciences in Delhi evaluated data from 2,714 of the hospital’s health professionals who showed signs of infection, according to a study published in The Lancet Infectious Diseases journal. They underwent RT-PCR testing between April 15 and May 15 as India was hit by its second primary Covid wave earlier this year.
Covaxin, a shot co-developed by the Indian Council of Medical Research (ICMR) and Hyderabad-based Bharat Biotech International Ltd, was administered only to AIIMS staff at the country’s immunization campaign in January.
According to a study published in The Lancet earlier this month, the vaccine’s adjusted efficacy against symptomatic Covid was lower two weeks or more after completion of a two-dose regimen than the 77.8 percent suggested by interim results during final stage tests. High infection rates and virus exposure among hospital staff, as well as the possibility that the then-newly emerging delta version lowered the shot’s protection, led to Covaxin’s poorer real-world efficacy, according to the researchers.
In a statement, Manish Soneja, an additional professor of medicine at AIIMS in New Delhi, said, “Our study offers a more complete picture of how BBV152 performs in the field and should be considered in the context of Covid-19 surge conditions in India, combined with the possible immune evasive potential of the delta variant.”
According to a study published in The Lancet earlier this month, the vaccine’s adjusted efficacy against symptomatic Covid was lower two weeks or more after completion of a two-dose regimen than the 77.8 percent suggested by interim results during final stage tests. High infection rates and virus exposure among hospital staff, as well as the possibility that the then-newly emerging delta version lowered the shot’s protection, led to Covaxin’s poorer real-world efficacy, according to the researchers.
In India, more than 130 million doses of Covaxin have been distributed so far. Bharat Biotech and India’s government, which has actively promoted the vaccine, had hoped to allay worries about the vaccine’s early approval in January, before it had completed phase 3 human testing, which had aroused widespread scepticism at the time.
After continuously prodding Bharat Biotech for further information, the World Health Organization’s independent technical panel granted Covaxin emergency approval in early November. According to Krishna Ella, chairman of the Hyderabad-based vaccine maker, the shot, which was manufactured using ordinary vated viral technology, took as long as it did because of criticism.
According to the researchers, the AllMs study did not measure the vaccine’s efficiency against hospitalization, severe sickness, or mortality. It also confessed that it wasn’t built to predict protection over various time periods. Patients were not investigated to check if their symptoms were caused by a specific variant, and the authors observed a paucity of information on comorbidities and prior illnesses.
In the wake of the fourth wave scare, an expert panel recommends narrowing the interval between Covishield dosages.
On Sunday, official sources stated that India’s main immunization body, NTAGI, has recommended giving the double dosage of COVID-19 vaccine Covishield between eight and 16 weeks after the first dose.
Under the National COVID-19 Vaccination Strategy, the second dosage of Covishield is currently given 12-16 weeks following the first dose.
The National Technical Advisory Group on Immunization (NTAGI) has not yet suggested any adjustments to the Covaxin schedule, which features a 28-day delay between doses, developed by Bharat Biotech.
The National Technical Advisory Group on Immunization (NTAGI) has not yet suggested any adjustments to the Covaxin schedule, which features a 28-day delay between doses, developed by Bharat Biotech.
The national COVID-19 vaccination programme has failed to incorporate the Covishield recommendation.
“The NTAGI’s most recent suggestion is based on recent global scientific evidence obtained from programmed data,” a source stated.
“According to it, the antibody response created when the second dosage of Covishield is given eight weeks onwards is practically equal when delivered at an interval of 12 to 16 weeks,” the source stated.
