COVID-19 Vaccine Safety: Balancing Rare Side Effects with Public Health Benefits – Frontline

In the US, more than 13,000 recipients of COVID-19 vaccines have filed injury claims with the federal government. In India, Venugopalan Govindans daughter Karunya died in July 2021 after taking the Covishield vaccine that was co-developed by AstraZeneca and Oxford University. He is contemplating moving the courts even though the national committee set up by the Indian government did not find sufficient evidence to conclude that her death was caused by the vaccine.

A new controversy has arisen in respect of Covishield because in February 2024 AstraZeneca admitted to a court in the UK that in very rare cases the vaccine can cause thrombosis with thrombocytopenia syndrome (TTS), in which blood clots form in unusual places, such as the brain and abdomen, with reduced blood platelet count. The patient suffers from many problems, including severe headache, shortness of breath, blurring of vision, and chest and abdominal pain. AstraZeneca informed the court that the causal mechanism is not known, that is, the biological process by which Covishield can cause TTS is unknown. Further, the company said that TTS is known to happen even in individuals who may not have taken Covishield. Incidentally, TTS has also been linked to Johnson and Johnsons vaccine Janssen.

The side effects of vaccines require serious attention. Apoorva Mandavilli, a reporter on science and global health and a member of the team that won the 2021 Pulitzer Prize for Public Service for coverage of the pandemic, wrote an article on May 3, 2024, in The New York Times, on the basis of her conversations with dozens of experts in vaccine science, policymakers, and people who said they had experienced serious side effects after receiving a COVID-19 vaccine.

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I was touched when I read the experience of Gregory Poland, a very well-known vaccine researcher whom I know personally. Dr Poland and I were members of a global consortium that carried out research on various aspects of different vaccines, including response, side effects, and so on, funded by the US National Institutes of Health. Dr Poland later served as the chief editor of the journal Vaccine. He told Mandavilli that he might never hear silence again; a loud whooshing sound in his ears has accompanied every waking moment since his first shot of a COVID-19 vaccine. He has written to the US Centers for Disease Control and Prevention (CDC) about his condition but has only received polite responses. If an internationally renowned vaccine researcher such as Dr Poland gets only a lukewarm response from the CDC, one wonders whether the common man facing a vaccine-related health problem will even elicit a response.

On May 5, 2023, the WHO declared that COVID-19 was no longer a public health emergency of international concern. But the virus is still killing people around the world. Various strains of SARS-CoV-2, the coronavirus that causes COVID-19, continue to circulate in most populations, including in India. There is always a chance that new variants will emerge and cause new cases and fatalities. One recalls that SARS-CoV-2 emerged in late 2019, and there have been seven million reported deaths from COVID-19. Because of weak systems of death registration, the number of reported deaths during the pandemic was a gross underestimate. A study published in the medical journal The Lancet found that although 5.94 million deaths due to COVID-19 were reported between January 1, 2020, and December 31, 2021, the estimated actual number of deaths in that period was between 17 and 20 million. The extent of underestimation varied across countries; India was among the top. For improved monitoring of pandemics in the future, it is necessary to strengthen death registration systems globally.

Due to weak systems of death registration globally, the number of reported deaths during the pandemic was a gross underestimate. | Photo Credit: Niranjan Shrestha/AP

The COVID-19 pandemic witnessed the triumph of science and technology. Multiple safe and effective vaccines were developed in record time and first authorised for emergency use in December 2020. Bharat Biotech developed an indigenous vaccine in collaboration with the Indian Council of Medical Research-National Institute of Virology. A wholly new class of vaccines (mRNA vaccine) was developed for human use, which resulted in the award of a Nobel Prize in 2023 to Katalin Karik and Drew Weissman. However, the scaling up of vaccine production took time. Therefore, the global distribution of vaccines was far from equitable, and overcoming it was a major challenge. India (notably, Serum Institute of India) played a major role in the scale-up operations to make the vaccine widely available.

Vaccine hesitancy was also a serious challenge. A systematic study on vaccine uptake published in March 2023 in Journal of Infection and Public Health found that [c]oncerns about COVID-19 vaccine safety, negative side effects, rapid development of the COVID-19 vaccine, and uncertainty about vaccine effectiveness were associated with reluctance to be vaccinated. False stories that COVID-19 vaccines are ineffective or that their side effects far exceed their benefits have been promoted by many influential people, including politicians. Facts indicate otherwise. A study by The Lancet Infectious Diseases estimated, on the basis of official reported COVID-19 deaths, that vaccinations prevented 14.4 million deaths from COVID-19 in 185 countries and territories in 2021. But, because many countries had banned the use of Covishield citing side effects, people in India have asked why the government here did not ban its use. Delhi Health Minister Saurabh Bharadwaj correctly demanded on April 30, 2024: The Central government should urgently address the alleged side effects of the vaccine because millions of people in India have been vaccinated with Covishield. As on that date, over 1.7 billion doses of Covishield had been administered in India.

The only way to prevent adverse events arising from vaccination and improve vaccines is by conducting scientific studies on vaccine safety, not by banning a vaccine because of the occurrence of very rare side effects. After all, no drug or vaccine is completely safe. Yet, we use these when the benefit of usage far outweighs the risk.

Of course, it is sad that Karunya died not long after taking Covishield. However, in order for her family to get compensation for her death, it must be proved on the basis of reliable and valid scientific evidence that her death was the direct result of the vaccine. This is not an easy task, particularly because an adverse outcome of vaccination, which may sometimes also result in death, is very rare. The WHOs Global Advisory Committee on Vaccine Safety calculated that the risk of TTS for a person living in the UK is 1 in 2,50,000 recipients of the AstraZeneca-Oxford vaccine, while for a recipient in the EU it is 1 in 1,00,000. We do not have an estimate for India, but it is expected to be similar.

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Occasionally, an adverse health outcome usually encountered after vaccination is also observed in people who did not take the vaccine. The background rate of TTS in the non-vaccinated population may be similar as reported in a study involving the health records of 38.6 million people in six European countries. Therefore, to scientifically prove that an adverse outcome is due to vaccination is inordinately difficult. Unfortunately, in India or even globally, there is not a central database where reports of adverse outcomes of vaccination are available. It is extremely important to create such national databases and preferably a global database. Fortunately, an international network has been formed with experts in vaccine safety, biology, and other relevant disciplines to conduct scientific studies on reported side effects of vaccines.

Also, fortunately, in spite of misinformation about vaccines and occasional reports of adverse events encountered after vaccination, the vast majority of people around the world still trust vaccines. The results of a survey conducted on 23,000 adults in 23 countries, published in Nature Medicine on April 29 stated: A total of 60.8 percent expressed being more willing to get vaccinated for diseases other than Covid-19 as a result of their experience during the pandemic. Based on a detailed analysis of the responses obtained in the survey, this report concluded that vaccine hesitancy and trust challenges remain for public health practitioners, underscoring the need for targeted, culturally sensitive health communication strategies. An even greater challenge is possibly overcoming the barriers of poverty and inequity in access to vaccines. The global health system must wake up to this challenge so that future pandemics can be prevented or if they occur can be, handled with less misery for humankind than one witnessed during the COVID-19 pandemic.

Partha P. Majumder is a National Science Chair (Scientific Excellence), government of India, and a former president of the West Bengal Academy of Science & Technology and the Indian Academy of Sciences.

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COVID-19 Vaccine Safety: Balancing Rare Side Effects with Public Health Benefits - Frontline