As Nigeria gets ready for delivery of COVID-19 vaccines, scheduled for this month end according to the Federal Government, experts have proferred warning concerning public attitude to the vaccines.
The United States Centres for Disease Control warn that when a vaccine requires two doses, patients must submit to the two doses within the specified timeframe.
“The first dosage helps your body to recognise the virus and gets your immune system ready, while the second injection strengthens that immune response. This makes your body more prepared to fight the infection,” CDC says in its advisory.
A former consultant to the World Health Organisation, Prof. Oyewole Tomori, warned that the COVID-19 vaccine is not the solution to the viral infection and that vaccination does not protect anyone from exposure and infection.
“The likelihood is that you will develop immunity but then, that immunity does not protect you from exposure, it does not protect you from infection. What the vaccination does is to prevent your infection from becoming a disease.
“Your vaccine will not protect you from exposure; if you don’t wear your mask and you go out because you are vaccinated, it does not mean that you won’t be exposed to somebody who is sneezing and carrying it around,” he said.
The virologist noted that the vaccine must be seen as an addition to other measures in mitigating the viral infection.
“The guarantee is that you are protected but supposing you are not and even when you are protected if you get exposed to the virus, it will grow in your body, that is the infection but it will not progress to disease because you have the vaccine.
“Vaccine is not the solution; it’s just an addition to the things we said we should be doing- wear your mask, wash your hands, and maintain your distance,” Tomori said.
Speaking about the vaccines and the dosages, the UK government-owned Medicines and Healthcare Products Regulatory Agency reported 80 percent success rate for the Oxford/AstraZeneca vaccine when two full doses are administered three months apart.
“The Pfizer/BioNTech vaccine guarantees 89 percent protection from two weeks after the first dose,” the agency said; adding, “the initial dose of Oxford/AstraZeneca vaccine offers as much as 70 per cent protection against the effects of the virus.”
Moderna says its vaccine was 80 percent protective after one dose, with efficacy peaking two weeks after the first vaccination.
Experts, however, warn that so far, there is no long-term evidence that any of the vaccines will offer lasting immunity based on just one dose, or how effective they will be if the second dose is delayed.
Indeed, BioNTech and Pfizer have warned that they could not guarantee that their vaccine would continue to be effective if the second dose is given more than 21 days after the first.
Experts urge the use of the vaccines in conditions exactly matching those of their trials as much as possible in real life situation.
So far, the National Primary Health Care Development Agency says the Federal Government is targeting administering the COVID-19 vaccine on 40 percent of Nigerians during the first batch this year, pointing out that 30 per cent are expected to be vaccinated in 2022.
The agency also said the Federal Government was also sourcing for vaccines from other countries like Russia.
It said the rate of infection in each state is the criterion to be used for the distribution.
Considering that the vaccines will not go round every Nigerian citizen in the next two years or thereabouts, experts however warn that the vaccines are not to be rationed.
Experts at the United States Food and Drug Administration say whoever receives the Moderna or Pfizer COVID-19 vaccines must get the two full doses if they must benefit maximally.
“We have been following the discussions and news reports about reducing the number of doses, extending the length of time between doses, changing the dose [half-dose], or mixing and matching vaccines in order to immunise more people against COVID-19,” FDA Commissioner Dr. Stephen Hahn and Dr. Peter Marks, who heads FDA’s vaccine division, said in an agency statement.
“These are all reasonable questions to consider and evaluate in clinical trials.
“However, at this time, suggesting changes to the FDA-authorised dosing or schedules of these vaccines is premature and not rooted solidly in the available evidence,” they warned.
Hahn and Marks also discouraged any attempt to mix the vaccines, such that an individual is vaccinated with two different brands.
“The available data continue to support the use of two specified doses of each authorised vaccine at specified intervals,” they warned; adding, “It’s understandable that people may want to stretch the vaccine supply, but it’s not safe to do so.”
“If people do not truly know how protective a vaccine is, there is the potential for harm because they may assume that they are fully protected when they are not, and accordingly, alter their behavior to take unnecessary risks,” they explained.
Another infectious disease specialist at the University of Pennsylvania, Dr. Paul Offit, added, “There’s no data on efficacy of a half dose. If you use a half dose, you’re just making it up.
“You’re just hoping that you’re right. Why would you dare to make up something when you don’t know whether or not it works?”
Earlier, the Director, Logistics and Health Commodities, National Primary Health Care Development Agency, Hajia Kubura Daradara, had said during a webinar hosted by the agency that government would not release the vaccines to the states until the states are ready to administer them.
She explained that states were expected to administer the vaccines within five days to retain their potency and that only states that showed commitment to this would receive the vaccines.
The Federal Government had said the first batch of the vaccines would arrive in the country between the end of January and February 2021, adding that the vaccines to be used in the country would be safe and effective.
It also said the 100,000 doses of the vaccine being expected in the first batch were for 50,000 Nigerians as the vaccines would be taken twice by each person at 21 days’ interval.
The Minister of Health, Dr. Osagie Ehanire, said previously that the country would spend N400bn to procure vaccines for the 70 per cent of Nigerians it planned to vaccinate, amid the rising spread of the virus as the nation goes through the second wave of the pandemic.
Meanwhile, speaking about the dosages, co-director of Mayo Clinic’s Vaccine Research Group, Dr. Richard Kennedy, noted, “For some people, the immune response after the first dose isn’t great enough to provide strong or lasting protection.
“Other people’s bodies may not respond at all. We give two doses to make sure we give everybody two chances for their body to create a response.”
Also speaking in favour of complete dosage, Associate Professor in the School of Medicine, University of Leeds, Dr. Stephen Griffin, said: “The Pfizer vaccine has been judged by the Joint Committee on Vaccination and Immunisation to confer 90 percent protection following the first injection, yet there is no data to support how long this might last and what may or may not happen if the second dose is delayed.
“This is also difficult to reconcile with data showing that robust antibody responses are coincident with the second Pfizer injection at day 21 – without data on appropriate patients, we should not merely assume that these will be the same if second doses are delayed.”
The JCVI is an independent expert advisory committee that advises United Kingdom health departments on immunisation, making recommendations concerning vaccination schedules and vaccine safety.
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