Coronavirus Pandemia and the Vaccine Race

This blog post will be focused on the race for a coronavirus vaccine that is happening globally. My main objectives here will be to explain in a general way how a vaccine works, to give some examples of successful ones, and the difficulty to develop specific vaccines for viruses. In addition, I will discuss some of the vaccines in the last clinical phases for the coronavirus and last, but not least, how it will get to you, me and to all global citizens when it is ready; this is the most complicated part. Just as a reminder today, September 1st, we have at least 850,000+ deaths and 25.5+ Million people infected by the coronavirus globally (data from the “Johns Hopkins University COVID19 Global Tracker”). We really need a vaccine to decrease the spread of this virus otherwise things will definitely get worse. Vaccines typically require years of research and testing before reaching the clinic, but scientists are racing to produce a safe and effective coronavirus vaccine by probably the beginning of next year (best estimate). To date, the number of vaccines under development worldwide are in the hundreds, however I will focus here on the ones that are in later stages in clinical trials with more possibilities of being successful. Researchers are testing 36 vaccines in clinical trials on humans, and at least 89 pre-clinical vaccines are under active investigation in animals (to see more information check “The NY Times COVID19 Vaccine Tracker” updated daily).

Types of Vaccines

Vaccines consist of five specific types: live attenuated microbial particles, inactivated microbes (by heat or any other methods), toxoid vaccines (part of the virus or bacteria that cause an immune response and immunological “memory”), conjugated or hybrid (most of it will be a non-pathogenic virus/bacteria with parts of it as targets) and new technologies such as nucleic acids (DNA & RNA) vaccines (for more information on vaccine types check this article). One example of a vaccine that used the attenuated virus is the polio vaccine that was able to almost eradicate the disease from the world (eradication just happened in Africa this week thanks to a lot of efforts from the WHO and its partners, but we still have isolated cases – check the article here).

Viruses and The Challenges Ahead

There are two types of viruses: DNA and RNA ones. They differ in the way they use our cells to produce more viral particles. The trickier ones are the RNA viruses since they use the cell machinery in a more successful way to “reproduce” and kill cells. For instance, the HIV virus is an RNA virus and until today researchers were not able to develop a vaccine mainly because HIV infects directly our immune cells, the ones that should “remember” and kill them in a second infection. For viruses causing infection in the respiratory tract such as the common flu, the H1N1 and now the SARS-CoV-2 it is not easy to develop vaccines. These viruses mutate a lot and the way our immune system “attacks” viruses can be different from other pathogens such a bacteria, for example. Additionally, each person has a different genetic background, thus different immune responses. This is why we are in this situation right now.

Vaccines Under Development

Let’s discuss some of the vaccines that probably will come first in the race and how they work: the AstraZeneca in collaboration with the University of Oxford in the United Kingdom (UK) and the Moderna Therapeutics in the United States of America. These are among the handful in Phase 3 clinical trials. Others include vaccines by Merck, the University of Queensland, GSK, Pfizer, Sinovac, Casino Biologics – the Chinese vaccine that was just reported, amongst others. Well, the AstraZeneca/Oxford and the Chinese Vaccine (their clinical study was just published on the well-respected journal The Lancet) use an adeno-associated virus genetically engineered as a “Trojan Horse” with an immunogenic protein (or an immunogenic part) of the Coronavirus (COVID19). It is difficult to explain right, but genetically engineered viruses have been used in research and clinical laboratories for research for decades. The idea here is that our immune system will fight “lightly” this foreigner hybrid virus and “create” a memory against it. The “secret sauce” for a vaccine efficacy and efficiency that we still do not know for the coronavirus is how long this immunological memory will last. For the polio virus one shot can last almost our whole lives, for the common flu and H1N1 we need to take it every year and probably from what I am reading about the coronavirus, we will need several shots during a single year based on the reports showing that the immunological “memory” doesn’t last too long. The Moderna vaccine uses a different approach based in nucleic acids. An RNA vaccine uses viral genetic material (in this case the coronavirus RNA) to produce antigens that would allow the body to learn to respond in a second infection by it. This is the first of this kind, that is why there is a lot of skepticism and concern. The last one that I wanted to write about is the “russian” vaccine that the media is discussing a lot recently. For me, as a scientist, if there is no data, no publication, no clinical trials and no information available I do not trust. The russians did not disclose anything: how the vaccine was developed, how it works, the tests that were done, if it is safe enough or not, etc.* To finalize, the most problematic part after all clinical and toxicological tests are cleared and the vaccine is ready is to produce it in large scale and distribute it globally.

What The Future Holds?

Several questions are still open to discussion based on the clinical scientific facts we have until now: Which country will get it first? How much a dose will cost per person? How many immunizations we will need to be safe and start walking around going back to normality? How the governments will deal with the bureaucracy to buy and distribute it to its citizens? We never had in my lifetime something involving so much money and interests in healthcare in a global scale like this. A lot of people can get filthy rich with the outcome of a successful vaccine, that is for sure. Thus, what the future holds in this race? Who will win? And, most importantly, when the first vaccine is approved what will be its immunological efficacy? 50%? 60%? Meaning that some people will not get the expected immune “memory”. Other factors that should be taken seriously are side effects of the vaccine (for example, in the Chinese vaccine study more than 90% of the group that received it had at least one side effect). Well, we are just watching this race and rooting for a good winner. I hope we will have something until the end of this year, and that it could reach every single person in the globe. A little utopic to think like this but we need to be positive. To close this post we still have an open question: Who will be the winner? What do you think?

*Footnote: An article describing a non-randomized phase I/II clinical study from Russia was published today, September 4th, with 76 people after my post was published. The strategy used was based on an engineered adeno-associated virus with an immunogenic protein from SARS-CoV-2. Even with a very low number of participants, the study is encouraging; however as stated in the Conclusions, the authors make it clear that further clinical investigation will be needed to test effectiveness. To check the full article in the journal “The Lancet” click here.

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