Covid-19 vaccine from Pfizer and BioNTech shows promising results. However, it led to fever and other side effects, particularly at higher doses.
A paper published on MedRXiv, a preprint server, revealed the first clinical data on the Covid-19 vaccine from Pfizer and BioNTech.
In the Pfizer study, 45 patients were randomly assigned to take one of three doses of the vaccine or placebo. Meanwhile, twelve receive a 10 microgram dose, 12 a 30 μg dose, 12 a 100 μg dose, and nine a placebo. Half of patients had fever with the 100 μg dose. They did not take a second dose at that level.
A second injection took place three weeks later of the other doses. Results showed that 8.3% of the participants in the 10 μg group and 75% of those in the 30 μg group had fevers.
Results showed that more than half of the individuals who took one of those doses manifested some kind of adverse event. This involved fever and sleep disturbances. None of these side effects was considered serious, meaning they did lead to hospitalization or disability and were not life-threatening.
The vaccine generated antibodies against SARS-CoV-2, the virus that develops into Covid-19, and some of these antibodies were neutralizing. This means they seem to stop the virus from functioning. Levels of neutralizing antibodies reached 1.8- to 2.8-times the level of that in the patients who recovered.
However, it is not certain that higher antibody levels can provide people immunity to the virus. To corroborate this thought, Pfizer will need to hold large studies that should prove that individuals who have received the vaccine are at least 50% less likely to become infected.
Those investigations could start by summer, mostly in the US. Pfizer will assess four different versions of the vaccine, but only one can be used for larger studies.
There are no pregnant women in the current study. In addition, no other data on the ethnic diversity of participants was presented, although the paper suggests that future studies must cover a more diverse group.
Meanwhile, the second dose, a booster shot, was need for immunity. The individuals who took the single 100 μg dose manifested lower antibody levels than those who took two shots of the lower doses.
According to the Milken Institute, 14 Covid-19 vaccines are currently in human trials. These include entrants from CanSino, Inovio, Moderna, and AstraZeneca. Others that are about to start are from Merck, Sanofi, and Johnson & Johnson. Overall, there are 178 vaccines are in different stages of development.
The basis of the Pfizer/BioNTech vaccine is a technology called messenger RNA, which employs a key genetic messenger in cells to produce protein that the immune system then attacks. Moderna has not yet released data on its vaccine but may do so anytime soon.
Not a cure-all solution
However, according to a virologist, coronavirus vaccine will not be a cure-all solution. No clear evidence exists that antibodies can provide absolute immunity.
Robert Lambkin-Williams, an independent virologist at Virology Consult Ltd, warned that a coronavirus vaccine cannot completely fight the pandemic and serve as the sole solution.
Speaking to CNBC’s “Squawk Box Europe,” he said the use of antibodies in fighting off the virus and protecting them from being reinfected with Covid-19 has not been proven yet.
“That’s important because we don’t know if the vaccines that encourage those antibodies to be produced are going to work,” he said.
He added that scientists still hope that antibodies would stop the coronavirus from penetrating individuals more than once.
