Call it a booster or a precautionary dose, but with the launch of its latest immunization program on January 10, India continues its fight against COVID-19. And it couldn’t have started sooner, as the highly contagious Omicron variant continues to increase the number of cases in the third wave of the pandemic. About 57.5 million people are eligible for the third shot, among them 27.5 million people over the age of 60, 10 million health workers and 20 million frontline workers. Eligibility can be checked on CoWIN, and prior consultation with doctors is advised.
To do so, all one needs is a mobile number or identity card to take the third shot. A booster dose is to elicit a stronger antibody response. While Indian government-approved ‘prevention’ doses are important for vulnerable people, virologists and other medical researchers also believe that it is important to assess the cross-immunity generated by mixing available vaccines. They recommend that the safety profile be well established before various vaccines are administered as preventative supplements.
Graphic by Tanmay Chakraborty
Apart from Covishield and Covaxin, seven other vaccines, including mRNA vaccine, which are easy to produce and easy to launch, have been approved. The mandatory two doses are expected to be given to everyone in the country over the next 4-5 months. Vaccines appear to be remarkably effective against all types in reducing hospitalization and saving lives. But long-term data on their use are not yet available. Vaccines are approved on a ‘reasonable basis’ based on information available less than a year later with the Emergency Use Authority (EUA).
“No vaccine, including mRNA vaccines, is protecting against infection,” says Dr Rakesh Mishra, director, Tata Institute for Genetics and Society, Bengaluru. “The advantage with the third wave is that we have a very large sero-positivity of about 80 percent or more, and many of the weaker ones enjoy a fairly high level of immune protection with one or two doses, although they are not protected.” Can go against infection.
He said, ‘If we do not change our mindset from dreadful corona to a severe winter, then it will be a big challenge. As a population, we will not be able to cope with it.”
– Dr. Jaiprakash Muliyal, Chairman, Scientific Advisory Committee, National Institute of Epidemiology
Although research data is scant, there is enough to show that antibodies decline six months after getting two shots of the vaccine. Hence the need for a booster dose. However, as Mishra points out, “boosters have limited value, which is why they are called a precautionary dose. We don’t have data to say whether those taking it enjoy a specific percentage of protection. This provides a modest top-up of antibodies, but we can’t say for sure yet. To call it Booster, we must have data on how it actually works. Now we don’t have. We know that vaccines are safe and it is good to provide additional protection to relatively more vulnerable people.”
cocktail puzzle
Although the Center has ruled against mixing vaccines for the time being, a mixed dose of CoviShield and Covaxin can certainly boost the spike protein-neutralizing antibodies and also increase vaccine effectiveness against Omicron, the Asian Institute’s founder- President Dr. D. Nageshwar Reddy says of Gastroenterology (AIG) hospitals and its subsidiaries Asian Healthcare Foundation. A study by AIG clearly confirms this, as none of the participants showed any adverse effects. “When the first and second doses were from different vaccines, the spike protein antibody response was four times higher than after two doses of the same vaccine,” he says. Spike protein-neutralizing antibodies kill the virus and reduce overall infectivity.
The AIG study also showed that 87 percent of the participants—those who had not been vaccinated and had never tested positive—had COVID antibodies. “This means that our population has developed significant antibodies against COVID, as we have faced the huge delta wave,” says Reddy.
However, epidemiologists are skeptical about implementing the third dose for vulnerable groups as a mainstay of India’s vaccination strategy, saying its added value is limited. He believes that overcoming vaccine hesitation and ensuring people get the first and second vaccine should remain the driving force. Several countries, such as the US, UK and Germany, are offering booster doses, even allowing vaccines to be combined with top-up anti-bodies for added protection.
“There is a need to adopt a holistic approach to run an effective vaccination programme,” says Mishra. “If given a choice, I would first vaccinate all the individuals on the planet with two doses and only then think about the third dose. It would be a bigger attack on the virus. It would reduce infection and give us fewer new forms.” And their spread has to be tackled.”
Policymakers are also reluctant to experiment with the cocktail strategy because of the risks involved, despite health experts pushing for it. So the government is trying to stick to its original target of 10 million immunizations a day, despite barriers to distribution and vaccination, and cover all adults and people aged 15-18 before the end of this summer.
unlucky OMICRON
The most worrying thing about Omicron is its contagiousness. Many do not even know whether they are infected or not, especially when the virus mimics the symptoms of the flu. Younger age group (3-15) are considered as carriers, contracting the infection without showing symptoms and clearing the disease with their strong immunity. The vaccines that are most appropriate for them are yet to be studied. With mild symptoms, many don’t even get tested. This gives the virus more opportunity to mutate and emerge in new avatars, taxes health care systems and introduces a new loop in the pandemic. Masks are thus the most effective protection against its spread. “Omicron is doubling in barely two days,” says Dr Jayaprakash Muliyal, chairman of the Scientific Advisory Committee of the National Institute of Epidemiology. “It’s faster and, in that sense, better than Delta. It shows little regard for past infections or vaccinations. Everything that’s available is based on the Wuhan virus. So multiple boosters won’t work against Omicron. “
Studies to date suggest that this variant does not affect the lungs like its predecessors and is mainly confined to the upper respiratory tract. Pathogenicity is low and virulence is slow. Studies from South Africa show that it is highly immunogenic and also has cross-reactivity to previous infections. It is an efficient immunogen. It builds immunity against itself and the speed with which it moved up and down in South Africa suggests that it may not be as dangerous as the delta. “If we do not change our mindset from the dreaded corona to a severe cold, it will be a big challenge and we as a population will not be able to face it,” says Muliyal. previously uninfected. Also, virus positivity is no longer the way to treat cases. He suggests rethinking the disease, starting treatment and confirming the presence of the virus. The purpose of vaccination is not to load antibodies into the body. Its purpose is to sensitize the immune system; Once sentient, it will fight back whenever it is asked to do so.
Vaccine Possibilities
Vaccine-makers say vaccination is the only immunity and, therefore, are working on new iterations for emerging conditions based on how the virus mutates. They refuse to develop a single vaccine for all types of treatment. Bharat Biotech, awaiting the results of the study, expects the three-dose vaccine to be effective against Omicron. “The depth of science is driving innovation in India,” says CMD Krishna Ella, who also plans to register a patent. “We are close to unveiling a nasal vaccine that will confer immunity and also help break down transmission.” They believe that in addition to being endemic to Covid-19, variants will continue to exist and behave like influenza, with one or the other type playing out in one region every year.
Last month, India provided two new COVID vaccines – Corbevax and Kovovax – to the EU. Corbevax was developed by Hyderabad-based biopharmaceutical firm Biological E in association with Baylor College of Medicine and Dynavax Technologies in the US. It uses a recombinant protein-based technology, which dates from the 1980s and is used in the hepatitis B vaccine. Containing proteins from the coronavirus, it arms the body to recognize the virus and launch an immune response against it. This is in contrast to covaccine, which contains the whole virus but in an inactivated form. And since this vaccine contains only part of the virus, an adjuvant is added to strengthen the immune response.
Covovax, a recombinant-based vaccine developed by US-based Novavax, will be produced by Pune-based Serum Institute of India. To develop this, the researchers isolated the part of the virus’s genetic sequence that produces the spike protein and introduced it into baculoviruses, or pathogens that attack insects, instead of using yeast as a corm. We do. Like all vaccines, Covovax tricks the immune system into believing it is under attack from the actual virus.
In addition to vaccines, molnupiravir—an anti-viral that its makers say can help with moderate COVID-19—has also been approved and 13 companies are ready to make the drug. But the Indian Council of Medical Research says that this drug is unsafe. Production will be ramped up by getting manufacturers to use available untapped production locations, such as the Integrated Vaccine Complex at Chengalpattu, Tamil Nadu, to achieve full immunization by mid-2022.
Meanwhile, US military researchers are developing a new “super vaccine” that can tackle all mutations of the virus as well as SARS-CoV-1, which was first discovered in 2003. Known as the Spike Ferritin Nanoparticle (SpFN) Vaccine, its creators say the shot generates strong binding antibody responses against the receptor-binding domain and spike proteins of all types of concern. The US military’s strategy is to develop a ‘pan-coronavirus’ vaccine technology that could potentially provide safe, effective and sustainable protection against multiple coronavirus strains and species.
Equally important is developing a robust public health surveillance system. Epidemiologists say there should be genomic surveillance in every state along with a comprehensive sampling strategy to track any changes. This would require regular testing of a certain number of samples from each part of each state. Some experts have warned that until the whole world is vaccinated against the virus, new Covid-19 variants will continue to appear. They argue that sharing vaccines is not only an act of philanthropy but also an act of pragmatism. World Health Organization data shows that the global COVID-19 toll in 2021, as of December 29, was 5,411,759, more than the combined toll from HIV/AIDS, tuberculosis and malaria in 2020. Vaccination is the only way forward.
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