• Josely Chiarella

The COVID19 vaccine challenge

Try asking people what they want most today, the vast majority will say “the COVID19 vaccine”. And a second question: Do you want the vaccine for you, for the world or for everyone? The answer is complex because it involves technical-scientific, immunological, economic and political aspects.

According to the Coronavirus Vaccine Tracker (in Aug 20th) there are more than 165 vaccines in development, 35 in human trials (any phase) and only in Brazil 4 in clinical trial phase 3. The most advanced and promising one seems to be the Oxford vaccine, apparently in despite of some side effect as fever, that is quite common for any vaccine, it can generate an effective immunological response. The second in the line is the Sinovac/Butantan Institute vaccine that uses a very traditional technology of inactivated virus and probably will give good results soon.

And what is a good result for a vaccine? Ideally a single shot of an inexpensive vaccine that achieves a high efficacy. Let us leave cost aside by the moment and focus on efficacy. It’s very acceptable for a pandemic, and FDA already mentioned that a 50-70% effective vaccine would be approved. So, rounding up the calculation a 50% effective vaccine protects half of the vaccinated population, keep in mind that some of these vaccines require 2 shots. In the case of a production facility able to produce 100 million doses of a vaccine, it will be possible to immunize 50 million people and just 25 million, i.e. 25% of people will be effectively protected.

Most of the ongoing trials are including volunteers from 18-59 years, it means that the high susceptible group aged over 60 will be tested later and will have access to the vaccine after this additional test approval. It’s very probable that first access to the vaccine will be offered to healthcare professionals, people working in transportation and safety and some comorbidities.

And now, the 1-billion-dollar question: for how long the protection rests? This is really an answer that it will be exceedingly difficult to answer in a short period of time and should not delay the start of vaccination campaigns.

But let us assume we have the best available vaccine and we need to produce it. Time is short and it is foreseen a shortage of some production inputs, as vials. The manufacturers are already getting prepared for a tremendous production increase to supply globally.

Finally, we have a million of vials of a good vaccine, by an affordable price disputed by governors with electoral purpose and nonprofit international organizations ready to offer to the global population. It is time for needles and syringes. The Brazilian Health Ministry announced that will buy 110 million syringes, the country current production capacity is 10 million per month, so it’ will be necessary to stimulate this segment and also consider to import a significant amount probably from China as the biggest international provider.

If you answered the question honestly by saying that you want the vaccine for you, be prepared for this reality, the vaccine will come when the steps of this obstacle race are achieved one by one.

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