Last week, Novavax announced results of its COVID-19 vaccine trials that are causing concern in the United States as new, more transmissible – 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 percent. But in South Africa, where the strain B.1.351 mainly circulates, the effectiveness has decreased to 50 percent.
Data from Johnson and Johson clinical trials yielded similar results. The company’s single-shot vaccine has 66 percent efficacy in a large-scale trial spanning three continents. In the US, the effectiveness of the vaccine has reached 72 percent. In South Africa it was 57 percent.
Although the headlines about the news about diminished efficiencies may seem worrying, epidemiologists say it is not yet time to panic. In the world of vaccines, the effectiveness of 50 percent is still impressive.
“The flu vaccine has an effectiveness of 36 percent,” says Dr. George Rutherford, a professor of epidemiology at the University of California, San Francisco. “The fact that we set the standard at 95 is just phenomenal; and it’s the best vaccine we have, it’s the measles vaccine.”
Both the Moderna and Pfizer vaccines are also more than 90 percent.
Rutherford said news of the protection of the Johnson & Johnson and Novavax vaccine against the new variant is very encouraging.
“It’s good protection,” Rutherford said.
Amesh Adalja, a senior scholar at Johns Hopkins Center for Health Security, agrees.
“You have to remember that the 50 percent figure reflects how effective it is in preventing symptomatic diseases, so it is not the same as serious illness, death and hospitalization, where it is very effective,” Adalja said. “The true story of the Novavax vaccine is therefore that even in the light of the South African variant, the Novavax vaccine prevents serious diseases due to COVID-19, prevents deaths by COVID-19, hospitalization by COVID-19.”
As explained by the World Health Organization, the effectiveness of the vaccine is the percentage of ‘reduction in disease prevention in a vaccinated group compared to a group that has not been vaccinated under optimal conditions.’ It should not be confused with the efficacy of the vaccine, which is the “ability of vaccine[s] to prevent outcomes of interest in the ‘real world’. “
Experts have warned in The BMJ that comparing the lower efficiency rate with the higher is a ‘mistake’, especially considering how Johnson & Johnson is expected to be a game changer in the international vaccination. Unlike the Moderna, Pfizer and Novavax vaccines, which all require two shots, Johnson & Johnson requires only one. It also has lower storage requirements which makes it flexible to store and apply.
“The real result is that a single-vaccine vaccine, which enables easy long-term storage and administration, provides complete protection against hospitalization and death,” Kevin Marsh, professor of tropical medicine at Oxford University, told The BMJ. “This is important because the immediate requirement of vaccination worldwide is to limit deaths as quickly as possible.”
The variant B.1.351 originated for the first time in Durban, South Africa. Scientists were concerned that the mutation of the virus is in the SARS-CoV-2 Spike, which obscures its appearance on the immune system, which may make it easier to circumvent immune protection. This is why scientists are seeing a decline in the effectiveness of the vaccine, which they predicted from the beginning.
There is cause for concern that the coronavirus is mutating where it is. However, any vaccine that is slightly mild can help prevent the spread of the coronavirus. This will have a domino effect, as lower transmission means fewer viruses repeat and thus mutate.
“Viruses cannot mutate if they cannot replicate,” said Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, said Monday. “If you stop its replication by vaccinating widely, you will not only protect individuals from disease, but you will also prevent the occurrence of variants.”
Adalja told Salon that the goal at present is not to eradicate the coronavirus, but to reduce serious outcomes.
“We will not get rid of this, it will not be eradicated like smallpox,” he said. “What we’re trying to do is awaken this virus, make it something more like the other coronaviruses that cause 25 percent of our colds by giving people immunity through a vaccine … so this is what this doing vaccines, people have forgotten that the endgame is here to prevent death. ‘
But what if new variants emerge and become smart enough to completely defraud our vaccines? Well, then scientists will have to change the vaccines. Adalja said it is ‘unclear’ at this stage whether this is something we will have to do in the future, but if we do, it is relatively ‘easy to do’.
“Novavax uses a recombinant platform that is very easy to customize,” Adalja said.
Rutherford said the vaccines may need to be adapted “as this virus develops.” Still, he is encouraged by news, specifically what has moved in the Israeli press. A man who had previously recovered from COVID-19 was re-infected with the B.1.351 strain, but the second time he had very few symptoms.
“It seems that gaining immunity has some protection against serious diseases, which we are trying to do,” Rutherford said.