The President of the Nigerian Infectious Diseases Society, and a professor of medicine and infectious diseases at Niger Delta University Amassoma, Dimie Ogoina, has stated that clinical trials suggest that the efficacy of COVID-19 vaccines may range from 60 to 97 percent and this means that of every 100 vaccinated persons, between 60 and 97 will be fully protected after vaccination.

Ogoina, who is also a consultant infectious diseases specialist and Chief Medical Director of Niger Delta University Teaching Hospital (NDUTH), Okolobiri, Bayelsa, said that most of the COVID-19 vaccines in use today will protect individuals against severe disease, hospitalization and death and, in some cases, the vaccines may protect a few persons from getting infected or from transmitting the infection if infected.

“Vaccines are rated based on their ability to protect a larger proportion of the population and no vaccine is 100 per cent protective”, he said. “Besides protecting the vaccinated individual, the major benefit of the COVID-19 vaccine is its ability to protect a larger proportion of the population from severe disease, hospitalization and death.

“Vaccines, like any other health intervention, are not 100 percent protective. It is not impossible for someone to die from COVID-19 after receiving full doses of COVID-19 vaccines. “Vaccination does not imply immunisation. For several reasons, some persons might be vaccinated without being immunized or protected.

“Some of the reasons might include receiving expired vaccines or vaccines that have lost potency due to improper storage, insufficient dosing, wrong technique or site of injection, and suppressed immune system or genetic factors that may suppress protection after vaccination”.

Noting that the actual duration of protection after vaccination was not yet established, he said: “It is also possible that immunity achieved from prior vaccination waned after some time.

“Consequently, it is possible that some might lose their immunity after a period even after receiving full doses of COVID-19 vaccines.”

Ogoina, however, insisted that barring some of the reasons stated above, COVID-19 vaccines have been shown to protect the majority of the population from severe disease hospitalization and death.

According to him, vaccines and the concept of vaccination is as old as the history of medicine and many years of vaccination has shown that vaccines are generally safe and highly effective in disease prevention.

“Currently, over 5 billion people across the globe and over 4 million people in Nigeria have received one or more doses of COVID-19 vaccines”, the specialist stated.

“The evidence suggests that COVID-19 vaccines are very safe and well tolerated by the majority of those vaccinated. Minor side effects such as fever, pain at the site of injection, and body weakness, among others have been reported following vaccination in some persons.

“However, these side effects are self-limiting and resolve within 1 to 2 days. Although a few cases of serious adverse effects have been reported following COVID-19 vaccination in Nigeria, there are no confirmed reports of death due to COVID-19 vaccines in Nigeria.

“It should be emphasized that death from COVID-19 vaccines is very rare. In Europe and America, the death rate due to COVID-19 vaccine is reported to be less than 0.002 percent.”

Giving reasons why people can die even when fully vaccinated, he said, before attributing any death to COVID-19, it was important to exclude other diseases that might have directly contributed to death.

“It is not unusual for people with COVID-19 to die from complications of diabetes or hypertension which may not be directly related to or caused by COVID-19”, Ogoina said.

“Many of these persons who succumb to COVID-19 after vaccination are likely to have lost their immunity or failed to develop sufficient immunity after vaccination”.

The specialist stressed that as a country, we ought to closely monitor and evaluate the COVID-19 vaccination strategy to ensure expired vaccines are not used for vaccination, vaccines are stored according to manufacturer’s specification, and administered according to standard guidelines.

“Since vaccination does not imply immunity, it is also necessary that we conduct research in Nigeria to determine if vaccinated individuals develop immunity against COVID-19 and, if they do, we need to know how long this immunity lasts and what factors contribute to no, short- or long-lasting immunity.

“We will need to identify our population at risk of no or short-lasting immunity and develop a plan to protect them. Notwithstanding limited supply of vaccines, our country ought to have a plan for administering booster doses of COVID-19 vaccines to vulnerable groups identified from local research.

“The campaign to inform all Nigerians about the benefits of COVID-19 vaccination should be factual, free of bias and consistent.

“Vaccines might not be 100 percent effective, but COVID-19 vaccines remain the most effective strategy to halt the challenge of COVID-19. In this era of new coronavirus variants, Nigeria can only be safe if the majority of the population get vaccinated”.

Vaccines part of solution, additional ammunition – Prof Tomori

Corroborating Ogoina’s views, a professor of virologist, Prof Oyewale Tomori, said people should understand certain things about vaccines as they are not the ‘be all or only solution’ to diseases but a part of the solution and additional ammunition in the defence armoury against diseases.

According to Tomori, just as you have different types of guns, bullets and other weapons of war, vaccines are prepared from the causative pathogen of a disease…either whole or parts of the organism, modified or weakened, so that instead of causing disease when injected into the body, the modified pathogen stimulates the body to mount a defense, in the form of antibodies.

“When next the body is exposed to the original unmodified pathogen, the already sensitised body rapidly produces antibodies to counter the pathogen, destroying it and preventing it from multiplying to cause disease.

“It is important to note the following: Not all vaccinations result in immunization or development of immunity or protection; that is, vaccination is not synonymous with immunization.