Last week, Novavax released the results of its tests with the COVID-19 vaccine, which are raising concerns in the United States as new, more communicable – and perhaps more deadly – variants emerge. In Britain, where a more transmissible strain known as s B.1.1.7 is the dominant strain, the two-dose vaccine had an efficacy rate of almost 89.4%. But in South Africa, where the B.1.351 strain is predominantly circulating, the rate of effectiveness has decreased to 50 percent.
Clinical trial data from Johnson and Johson produced similar results. The company’s single injection vaccine was 66 percent effective in a large-scale trial that spanned three continents. In the USA, the vaccine’s effectiveness reached 72 percent. In South Africa, it was 57%.
While the headlines that report low-efficiency news may seem alarming, epidemiologists say it is not yet time to panic. In the vaccine world, the 50% effectiveness is still impressive.
“The flu vaccine is 36 percent effective,” said Dr. George Rutherford, professor of epidemiology at the University of California, San Francisco. “The fact that we set the standard at 95 is just phenomenal; and this is the best vaccine we have, which is the measles vaccine.”
Moderna and Pfizer vaccines also have more than 90%.
Rutherford said the news about the protection of Johnson & Johnson and Novavax vaccines against the new variant is “very encouraging”.
“This is solid protection,” said Rutherford.
Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Safety, agrees.
“You have to remember that this 50 percent figure reflects how effective it is at preventing symptomatic diseases, so this is not the same thing as serious illness, death and hospitalization, where it is highly effective,” said Adalja. “Therefore, the correct history of the Novavax vaccine is that even in the face of the South African variant, the Novavax vaccine prevents serious COVID-19 diseases, prevents COVID-19 deaths, prevents COVID-19 hospitalization.”
As explained by the World Health Organization, vaccine efficacy is the percentage of “reduced incidence of disease in a vaccinated group compared to an unvaccinated group under ideal conditions.” This should not be confused with the effectiveness of the vaccine, which is the “capacity of the vaccine[s] to avoid results of interest in the ‘real world’. “
Experts warned in The BMJ that comparing the lowest efficacy rate with the highest is a “mistake”, especially considering how Johnson & Johnson should change the game in international vaccine launches. Unlike Moderna, Pfizer and Novavax vaccines, which require two injections, Johnson & Johnson requires only one. It also has lower storage requirements that make it more flexible to store and manage.
“The real result of the headlines is that a single injection vaccine, capable of easy storage and long-term administration, offers complete protection against hospitalization and death,” said Kevin Marsh, professor of tropical medicine at the University of Oxford, at The BMJ. “This is important, because the immediate requirement for vaccination globally is to limit deaths as quickly as possible.”
Variant B.1.351 first appeared in Durban, South Africa. Scientists were alarmed that the virus mutation is at the peak of SARS-CoV-2, disguising its appearance for the immune system, which may make it easier to get around immune protection. That’s why scientists are seeing a decrease in the vaccine’s effectiveness, which is what they predicted would be the case from the start.
It is worrying that the coronavirus is mutating where it is. However, any marginally effective vaccine will help prevent the spread of the coronavirus. This will have a domino effect, since the lower transmission means less virus replicating and, therefore, mutating.
“Viruses cannot mutate if they cannot replicate,” said Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, on Monday. “If you interrupt your replication by vaccinating widely … it will not only protect individuals from contracting disease, but also prevent the emergence of variants.”
Adalja told Salon that the goal now is not to eradicate the coronavirus, but to decrease serious results.
“We are not going to get rid of it, it will not be eradicated like smallpox,” he said. “What we’re trying to do is to neutralize this virus, make it look more like the other coronaviruses that cause 25 percent of our common colds, giving people immunity through a vaccine … so that’s what these vaccines are doing, people are forgetting that the final game here is to avoid death. “
But what if new variants appear and become smart enough to completely mislead our vaccines? Well, scientists will have to modify vaccines. Adalja said it is not “clear” at this point whether this is something we will have to do in the future, but if we do it, it is relatively “easy to do”.
“Novavax uses a recombinant platform, which is very easy to modify,” said Adalja.
Rutherford said vaccines may need to be modified “as the virus evolves”. Still, he is encouraged by news, specifically what has been reaching the Israeli press. A man who previously recovered from COVID-19 was infected again with the B.1.351 strain, but the second time he had few symptoms.
“Naturally acquired immunity appears to have some level of protection against serious illness, which is what we are trying to do,” said Rutherford.