Covid: 3 confirmed facts and 3 doubts about the future of vaccines, according to a Brazilian scientist from Oxford

Director and co-founder of the Master’s Program in Vaccines at the University of Siena, Italy, Clemens is also Professor of Global Health at Oxford University, UK, and works in the Department of Clinical and International Relations at the Carlos Chagas Institute in Rio de Janeiro.

The doctor is also a senior vaccine development adviser at the Bill & Melinda Gates Foundation, and was directly involved in creating rotavirus and HPV vaccination devices.

During the current pandemic, she served as director of the Oxford-Brazil Vaccines Group and was one of the coordinators of clinical trials demonstrating the efficacy and safety of the AstraZeneca/Oxford University vaccine. Part of these studies were conducted in our country.

According to the expert’s analysis during the event, the vaccination against Covid disease brought a series of lessons and legacies, such as the establishment of clinical research centers in different parts of the world and knowledge about the combination of different technologies, but there are still many challenges. Such as the need to expand the production of potions and protect the population of the entire world.

Clemens began his speech by recalling two recent global health crises: the H1N1 pandemic in 2009, and the Ebola epidemic, which has affected some African countries since 2014.

“In these two cases, efforts were made to create vaccines, but the products arrived a bit late or had problems at the production and regulatory stage,” his analysis said.

“But when we think specifically about Ebola in 2014, we see that this episode helped make the world aware of the need to invest in technology and innovation to prevent epidemics and epidemics,” he said.

This document, which is updated from time to time, has allowed for greater focus on the infectious agents of greatest concern, which must be sought in methods of prevention and treatment.

“Since then, we have had a greater awareness from governments and institutions that we need to accelerate the development of vaccines for pathogens that can cause epidemics,” the expert explained.

Clemens also noted that one of the biggest barriers when it comes to researching new immunizing agents is the difficulty of conducting larger clinical trials, involving up to tens of thousands of volunteers, the investment of millions of dollars and vast infrastructure.

To respond to the COVID-19 pandemic and develop solutions in record time, it was necessary to address this issue.

“Some institutions have started to fund the organization of research centers in different parts of the world,” he said. “In four months, we were able to train and set up 22 clinical trial sites in seven countries in Latin America.”

“It was these centers that helped the world validate the vaccines and start producing the doses that were used in recent months,” Clemens added.

The doctor explained that in the case of the AstraZeneca vaccine, the negotiation process to bring clinical research to Brazil began in April 2020. Tests began in mid-July of that year, and in November, the efficacy and safety of the product was demonstrated.

“In about eight months, we were able to validate the immunizing agent that would become one of the largest suppliers to the Covax facility. [instrumento internacional de compra e distribuição de doses para os países mais pobres]”, He said.

Launching and sustaining a global vaccination campaign against a new disease that kills thousands every day has been a formidable challenge.

Clemens notes that this whole process, which is still ongoing, has brought a series of lessons learned and required adjustments along the way.

The first fact mentioned by the doctor is the increase in the time period between the two doses and heterogeneous regimens (in which one takes AstraZeneca and then Pfizer, for example).

“When we develop vaccines, it is not enough to prove that they are effective,” he said. “We need to monitor persistence of antibodies, effectiveness of doses and, ultimately, campaign adjustments.”

“Increasing the interval between the first and second doses, for example, was very important, as we were able to vaccinate more people in times of scarcity.”

Brazil itself used this strategy early in the first half of this year: Two doses of Pfizer or AstraZeneca were applied about three months apart. In this way, it was possible to protect a significant part of the adult population, if only partially.

The second aspect that has become emphatic in recent months is the need for booster injections.

The first recipients of the third vaccine were the elderly and individuals with compromised immune systems, but the arrival of new variants (delta and micron status) precipitated the need to ensure additional protection for almost all groups.

“The efficacy of two doses of the vaccine against Omicron is less, it is about 40%. A third dose increases this rate to 70% or 80%. Therefore, if there is a possibility to give the booster, it is better that it has been analyzed,” Clemens analyzed.

Currently, in Brazil, the third dose is guaranteed for all people over 18 years of age. According to the latest Ministry of Health announcements, this booster should be given four months after a complete initial immunization (in two doses, in the case of those who received CoronaVac, Pfizer and AstraZeneca, or in a single dose, in the case of those who received Janssen).

The last certainty on the list concerns the unequal distribution of vaccines across the planet.

“These days I was interviewing for a project with candidates from Eritrea and Africa, and they told me that vaccination against COVID-19 practically did not start there,” he said.

The researcher warned, “As long as we don’t inoculate everyone, we will continue to act as a storehouse for new variants. And that’s exactly what we just saw with the emergence of omicrons.”

As much as science has found many answers in record time to deal with the pandemic, there are some important questions about the future of vaccination against COVID-19.

The Brazilian scientist considers that the first and second questions in this list are related to the period of protection of vaccines and whether it is necessary to conduct annual vaccination campaigns, such as what happens with influenza.

“We still need to understand the dynamics of the variables, whether any of them will become dominant and how this scenario will change from now on,” he said.

He added, “It is possible that we will have an annual vaccination for some age groups, but not for everyone. It remains to be seen whether and how long we will need to adapt the doses.”

All of this uncertainty is caused by not having enough time to gauge how long immunity lasts after vaccination, or how defense cells and antibodies react to protect us from infection with the coronavirus (or its more severe forms) months or years later.

“We study each vaccine platform, how long the protection lasts, and what the persistence of antibodies is over time…,” Clemens listed.

In conclusion, the last question may represent hope: will it be possible to use only half a dose of the vaccine as a booster?

Clemens explained that studies in this area are underway. If the responses are positive, this could be one of the best news in the coming months.

“With half a dose, we can vaccinate more people faster,” the doctor predicted.

“This would expand our capacity at a time when there is a shortage of infrastructure, materials and labour,” he added.

“We are lagging behind in increasing production and vaccinating the world, especially Africa, faster,” he concluded.

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