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Can Sri Lanka afford vaccine boosters?

08 Aug 2021

  • The wisdom of following developed countries’ example of a third vaccine dose
By Sumudu Chamara The evolving nature of the virus that causes Covid-19 has compelled health experts to rethink their approaches to preventing the disease, and caution people to be extra vigilant regarding the Covid-19 safety guidelines. In light of the discovery of new variants that have been found to be more aggressive and contagious, the health authorities have warned that the number of infections a single infected person can cause has increased, while wearing two masks instead of one is advisable. Despite various discussions and doubts about the vaccines, global health experts maintain that they are highly effective against a majority of new variants, and that the efficacy of the vaccines and the ability of a vaccinated person to fight an infection remains high for months, and in some cases, years. While some vaccine manufacturers have claimed that even one dose can induce considerable protection against the virus, there is also a discussion among the medical community about a booster dose (third dose) for fully vaccinated people.  Booster dose for Sri Lankans? In a context where a significant number of Sri Lankans have already received at least one dose of some vaccine, Director General of Health Services (DGHS) Dr. Asela Gunawardena, speaking to the media last week, said that discussions are underway to give healthcare workers a booster dose to further strengthen their immune system, taking into account the likelihood of them contracting the virus, even after being fully vaccinated.  He said that even though a large number of healthcare workers have already been fully vaccinated, there is a risk that they can still contract the virus; such infections (post-vaccination infections) have been reported from several hospitals in the country. He added that healthcare workers received their first dose of the vaccine in January and February, and their second dose in April. Meanwhile, National Operation Centre for Prevention of Covid-19 Outbreak (NOCPCO) Head Army Commander Gen. Shavendra Silva yesterday (8) said that the President has paid attention to whether a booster dose should be deployed in the country, and that the matter was discussed at the task force established to manage the pandemic. Speaking to TV Derana, he noted that some countries have already started this process, and that it was also taken into consideration when discussing the implementation of this measure in the country. As a result of these discussions, he said, the President has given instructions to make a request to obtain the required quantity of vaccines. Adding that Sri Lanka’s successful vaccination drive is a result of prompt administration of the first and second doses, Gen. Silva further stated that even though specific age groups have not been identified for receiving the booster dose, the President had issued instructions regarding obtaining more doses. Booster dose: need and importance Due to the aggressiveness and contagiousness of the virus, and especially its new variants, some countries have paid great attention to giving a booster dose to the fully vaccinated. However, health experts are still considering the need for a booster dose, while the protection a booster dose can provide is being debated. However, as of last month, none of the prominent health authoritative bodies have stated that a booster dose is necessary, and some experts have stated that even though the vaccine-induced immunity may not last for a lifetime, the vaccines’ efficacy and the body’s ability to fight the virus can last for years. A booster dose is just an extra dose of a vaccine, administered with the aim of prolonging protective immunity, particularly if there is evidence that protection is waning after a period of time, according to Yale University School of Medicine Infectious Diseases Expert Dr. Albert Shaw. He also noted that this series of three doses is recommended because a person needs extra doses for longer lasting protective immunity. “While a booster dose sometimes is an exact replica of the initial vaccine(s), it can also be tweaked, and when it comes to Covid-19, this is key, because the vaccine could then be tailored to target particular variants of the virus.” Adding that the current vaccines are still effective against the variants the world is seeing, particularly for protecting against serious illness that would require hospitalisation or cause death, he said that if the virus evolves further and there is a worse variant, however, the vaccine could be modified. Medical experts and studies say that vaccine-induced antibody levels decline over time, but they are still trying to figure out whether this decline means decreased protection against Covid-19, and the rate of loss of protection.  Recently, Israel’s health authorities released data on vaccinations and infections from December 2020 to July 2021, estimating that the protection provided by vaccines against infections had dropped from over 90% in the early months of vaccination to approximately 40% by late June.  In this regard, in an article published on Yale Medicine, Dr. Shaw had further said that checking antibody levels can give some level of understanding on how much protection lasts. However, he noted that even if they have waned, it does not necessarily mean the body’s capacity to respond to exposure is gone. He added that if a person is re-exposed to something via a booster shot following the original exposure by vaccination, the memory response is even more vigorous than the original, and this memory response includes antibody responses, but also includes an additional arm of the immune system controlled by a different group of white blood cells, called T cells. Studies suggest that authorised vaccines offer protection against even the new variants of Covid-19, and a preliminary study, which has not been peer-reviewed yet, had found that the Pfizer vaccine was 88% effective against the delta variant. However, booster doses may be needed for immunocompromised people (those with an impaired immune system). Some studies have shown that a considerable percentage of kidney transplant recipients and a third of dialysis patients fail to produce antibodies even after vaccination. Medications that some patients (fully vaccinated before the study) are on have been found to be suppressing the patients’ immune system, resulting in lack of antibodies. The studies have shown that after a booster dose, some patients were able to develop an antibody response.  However, there are mixed findings about whether a person obtaining a third dose has to match said dose with the first and second vaccines, or whether they can mix and match vaccines. The global situation According to foreign media, countries such as Germany, France, and Israel are planning to proceed with plans to give citizens a booster dose, predominantly due to the delta variant, regardless of the WHO’s call for a delay in implementing such plans. Recently, French President Emmanuel Macron said that France was planning to give a booster dose to the elderly and vulnerable from September this year, while Germany has announced its plans to give booster doses to immunocompromised patients.  Also, recently, Israeli President Isaac Herzog received a booster dose, which started a campaign to deliver booster doses to people over the age of 60 in the country, while Israeli Prime Minister Naftali Bennett has urged elderly citizens, particularly those above 60 years of age, to get a booster dose, claiming that they are six times more susceptible to severe illnesses and even death.  In addition, the US has signed an agreement with US-based Pfizer Inc. and Germany-based BioNTech to purchase around 200 million additional doses of vaccines, which foreign media said was for paediatric vaccination, and possibly for the administration of a booster dose.  Meanwhile, Covid-19 vaccine manufactures Pfizer and BioNTech have announced that they would seek permission from US regulators to authorise a booster dose of their vaccines, based on evidence from Israel and their own studies suggesting reduced efficacy six months after vaccination. However, US regulators i.e. the US Food and Drug Administration (FDA) and Centre for Disease Control and Prevention (CDC), had said that Americans who have been fully vaccinated do not need a booster shot at this time and that the vaccines remain highly effective against severe diseases and even death. Britain has started planning a vaccination drive to deliver booster doses, based on medical experts’ opinion that it might be necessary for the elderly and vulnerable groups. Among other countries that have planned or are planning to give a booster dose are Sweden, Finland, Indonesia, Thailand, Cambodia, Russia, Singapore, South Korea, and Switzerland. Vaccine inequity The discussion about giving a booster dose takes place in a context where the World Health Organisation (WHO) has advised to delay administering a booster dose until the end of September, due to the very limited supply of vaccines. WHO Director General Dr. Tedros Adhanom Ghebreyesus said last week that the world needs an urgent reversal from the majority of vaccines going to high-income countries, to the majority going to low-income countries. He added: “The WHO is calling for a moratorium on boosters (booster dose) until at least the end of September, in order to enable at least 10% of the population of every country to be vaccinated. I understand the concern of all governments to protect their people from the delta variant; but we cannot, and we should not, accept countries that have already used most of the global supply of vaccines using even more of it, while the world’s most vulnerable people remain unprotected.” According to the WHO, high-income countries have administered approximately 50 doses for every 100 people in May, and the numbers have since doubled, while low-income countries have been able to administer 1.5 doses for every 100 people, owing to the prevailing lack of supply. Vaccine inequity will have a lasting and profound impact on socio-economic recovery in low and lower-middle income countries, without urgent action to boost supply and assure equitable access for every country, including through dose sharing, according to new data released by the United Nations Development Programme (UNDP), WHO, and the University of Oxford. The WHO also said that while richer countries are projected to vaccinate quicker and recover economically quicker from Covid-19, poorer countries have not even been able to vaccinate their health workers and most at-risk populations and may not achieve pre-Covid-19 levels of growth until 2024.  “Vaccine inequity threatens all countries and risks reversing hard-won progress on the Sustainable Development Goals (SDGs),” the WHO warned. In fact, giving citizens a third dose is a discussion limited mostly to financially stable nations, as most low and middle-income countries are still struggling to get their hands on sufficient vaccines to give first or second doses to their citizens. However, overall, medical experts are of the opinion that while a booster dose can help boost the immunity of a vaccinated person, there are no adequate reasons at this time to suggest that it is absolutely necessary, unless in exceptional cases, such as those who have an immunity system that requires more doses to gain substantial immunity against Covid-19. Also, there are mixed responses from experts as to when a booster dose should be administered, as different studies show different results about how long the efficacy of each vaccine lasts. In this context, while providing a booster dose could be beneficial, it has to be done based on a properly conducted study about the state of immunity of the people who are to receive a booster dose. With vaccines being such a vital commodity in scarce supply, we may also have to wait until a larger portion of the general population, both globally and in Sri Lanka, receive both doses of a vaccine before even considering a booster; otherwise we may come to a situation where one portion of citizens is well protected, while the vast majority remains vulnerable.


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