COVID-19 vaccines, the silver lining of 2021?

  • Catarina Santos
  • 22 December 2020

The first two COVID-19 contender vaccines are the first ever mRNA vaccines, one from Pfizer and BioNTech and another one from the US company Moderna.

With the prospects of soon-to-come COVID-19 vaccination, general optimism might rise about going back to normal: traveling, vacations abroad, large face-to-face meetings, parties and family gatherings. However, one question still stands: By when?

The first two COVID-19 contender vaccines are the first ever mRNA vaccines, one from Pfizer and BioNTech and another one from the US company Moderna. These vaccines are described to be 95% and 94% effective, respectively, at preventing COVID-19 when compared to placebo (control group with no active vaccine). mRNA vaccines work by introducing in the body (via injection in the arm muscle) of a synthetic messenger RNA sequence from the virus. This contains the genetic instructions that allows the human cells to produce a viral protein (spike protein). Since only a part of the protein is made, it is not expected to cause harm to the vaccinated person, and it will generate immunization in a percentage of vaccinated individuals.

Both the UK and the US regulators have already approved Pfizer’s vaccine and EMA (the European Medicines Agency) approval is expected by 21st Dec. The Moderna vaccine is likely to be approved in the US still in 2020 and by EMA in January 2021.

Several vaccines, some with technologies other than mRNA, are currently being developed, namely by Astrazeneca & Oxford University, by Johnson & Johnson, by the German CureVac, by the French Sanofi together with the British GSK, to name a few. These other vaccine plans, if granted efficacious, safe and timely, seem important to accelerate, broaden and diversify vaccination plans worldwide. Why do we need several different COVID-19 vaccines? The main reason is that no single vaccine supplier is expected to cover the urgent need to protect over 7 billion humans. Both Pfizer/BioNtech and Moderna have plans to produce over 1 billion doses each in 2021. This does not seem enough to reach herd immunity, described to require vaccination of 60-75% of the population, with two doses per person. Also, production might be more difficult than expected as Pfizer and BioNTech recently announced that due to raw material scarcity, the production capacity would drop 50% from 100 to 50 million doses in 2020.

To diversify suppliers and minimize the risk, the European Commission pre-ordered vaccines from several prospective suppliers on behalf of all 27-member states. The EU, with a population of about 450 million, seems to have supply agreements with Pfizer, Moderna, AstraZeneca, Johnson & Johnson and Sanofi for a combined 1.4 billion doses, toped just recently by a new agreement to buy up to 405 million doses from the European company CureVac. These suppliers are expected to have received millions of euros to set up production facilities and to reserve vials for the EU at a set price. The deal seems to be that upon approval, vaccines are gradually sent to every EU country in proportion to its population. However, just recently both Astrazeneca and Sanofi reported deçlays on their respective vaccine plans, so the scarcity perception increased. Some European countries, beyond the EC deal, seem to be dealing directly with suppliers, like Germany’s side deals with BioNtech and other German drugmakers for a total of 300 million doses, more than enough to inoculate its population of 83 million. Another example is Hungary’s potential deal with Russia for the sputnik vaccine.

Since demand largely exceeds supply, prioritization is also key. The National Academies of Sciences, Engineering and Medicine, in Washington DC, upon request from the NIH and the CDC, produced a framework for the equitable allocation of the vaccine, based on three ethical principles:

  • Maximum Benefit, meaning that vaccines should protect first those most at risk.
  • Equal Concern, meaning that every person has equal dignity, worth and value.
  • Mitigation of Health Inequities, meaning that populations with the greatest burden from the disease should be prioritized.

Many countries have already defined as priority, vaccinating first those who are at most risk of infection with serious outcomes, as well as those who are considered essential for societal functioning: the elderly populations and health care professionals (HCP). However, there are yet many concerns: How much pressure will countries/institutions apply on the providers to satisfy their needs first? Will executive orders force or push for America first? How will countries guarantee the ruling principles? How to deal with priority individuals opting not to be vaccinated? Also, when more vaccines are available, with different technologies, will individuals be able to choose?

Beyond scarcity, countries are facing a different challenge: a growing number of vaccine skeptics. A survey published by Ipsos for the World Economic Forum shows that a growing 30% of surveyed (more than 18,000 adults in 15 countries including Europe) would not get a vaccine for COVID-19 if it were available. The main reasons for skepticism seem to be the vaccine side effects and/or the belief that vaccines moved through clinical trials too fast. It seems true that the current follow-up periods for the vaccines are too short to assess long-term protection as well as to capture rare, more serious side effects. There are also questions regarding vaccination of previously infected, vaccination of children and young, vaccination of covid-19 infected, individual vaccine preferences (mRNA vs other) among others. However, it might be important to work on strategies that help people understand that the benefit-risk profile of the vaccines seems positive and that vaccination is a key tool to getting lives back on track and prevent further infections and deaths. Until then, the prevention guidelines like wearing masks or social distancing will likely remain active.

Let’s keep the faith that scientific institutions, governments and society will act fast and responsibly so that a collective immunity to this virus will shine sooner than later.


  • Catarina Santos
  • PhD from New York University and Faculdade de Ciências da Universidade de Lisboa