The scientific community warns of the possibility that the formula for a Covid-19 vaccine will never be developed. Some governments seem to get used to it and remain cautious about the progress of clinical trials.
Many difficulties are added to the usual length of clinical trials to which vaccines are subjected. According to the Guardian, the particularity of SARS-CoV-2 compared to other coronaviruses is one of the explanations for these difficulties.
Short-term immunization
Lessons learned from finding vaccines for SARS and MERS could be invaluable in the race to find the one against Covid-19. However, this vaccine is still very difficult to define. It was envisioned at the start of the epidemic that people recovered from the virus had long-term immunity. Scientists are now questioning this assumption.
Research from the University of Oxford recently analyzed the blood of patients who have recovered from the disease. The test results showed that their levels of antibodies that allow long-term immunity increased sharply during the first month after infection, but then dropped suddenly. “If natural infection does not offer an interesting immune response, except in case of severe infection, what more can a vaccine do?”, wonders researcher Stanley Perlman.
Finding a vaccine also means assuming that the virus does not mutate. However, for the Covid-19, nothing is less certain. If it were to mutate, the vaccine would be ineffective because the antibodies present in the one that would be administered could no longer protect us or offer immunization against the virus. For Martin Hibberd, virologist, the mutations already observed constitute a “alert” as to the usefulness of a potential vaccine.
Do not confuse speed and precipitation
To rush research and promise a vaccine in eighteen months is to risk paying insufficient attention to the side effects. When the first SARS virus was detected in 2004, one of the vaccines developed had caused hepatitis in the animals it was tested on. Another vaccine in the testing phase had caused severe lung damage to laboratory animals, making them more susceptible to future infections.
The director of the Worldwide Influenza Center, John McCauley, believes that it is necessary to take the time to analyze the difficulties that each vaccine can cause: “We don’t know the difficulties, the specific difficulties with which each vaccine can confront us. And we don’t have enough experience managing this virus or these components. ”
Partially effective vaccines
There may not be an ideal answer to the Covid-19. Some vaccines may be effective, but nothing is yet certain. Other formulas have proven their effectiveness, not for the prevention of the virus but for that of the fatal diseases caused by the coronavirus. Producing a vaccine against this virus would not prevent 100% of infections, but would reduce the number of deaths.
The solution could lie in a compromise between several vaccines. For the youngest, a vaccine with a powerful strain of the virus, because their organisms are more robust and can absorb it. It will protect them strongly and will last several years. In older people, scientists may lean toward using a vaccine with reduced efficacy against the disease, but which prevents deadly infections.
Either way, the coronavirus could be a part of our lives for a long time, and play “Ping-pong in time and space” with different countries, according to Larry Brilliant, director of a smallpox research organization.
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