The WHO chief scientist confirmed that the organization is following closely and very carefully whether there is any evidence of a relationship between the vaccine and its side effect.
The chief scientist of the World Health Organization, Dr. Sumiya Swaminathan stressed the need to obtain the second dose of any vaccine consisting of two doses, explaining that the importance of the second dose of vaccines, which is obtained through two doses, is due to being the dose that gives an actual boost to the immune system so that it is The antibody response, as well as the response of mesenchymal T cells, is very strong.
Dr. Swaminathan added that the second dose also develops the memory response, which in turn makes the effect of the vaccine last for a long time, as when the body detects this antigen or viral protein again, it knows it needs to respond quickly.
No harm in serving or being late
Dr. Swaminathan’s statement came during an interview with Vesmita Gupta Smith, in episode No. 26 of the televised magazine “Science in Five”, which is broadcast by the World Health Organization on “Twitter” with the aim of raising awareness and education about everything related to the emerging corona virus, its mutated strains and vaccines against it. .
The appropriate intervals between the two doses of the vaccine
Dr Swaminathan explained that many vaccines are now in development, and each is being given on slightly different dosing schedules. Most of the vaccines that are developed need at least two doses, but there are some single-dose candidate vaccines as well, indicating that the interval between doses depends on the type of vaccine that is obtained, and the local medical authorities and ministries of health in each country undertake the task of developing guidelines and determining The date of vaccination with the second dose of the vaccine.
And she went on to say that the two doses of the vaccine are currently given within a period of three to four weeks, but there are some data on some vaccines, including the AstraZeneca vaccine, which revealed that delaying the second dose for up to 12 weeks gives a better immune boost. Dr. Swaminathan stressed that the second dose should not be missed, but there is no problem when delaying, as it is important to get the second dose if the vaccine consists of two doses, regardless of whether the second dose is obtained a few days before its due date or at a late date. For a few days or even two weeks.
But it is important to go back and get the second dose because the first dose actually introduces this new antigen to the immune system to prepare it, while the actual push for the immune system to build the capacity for the antibody response, as well as the intermediate T cell response, is achieved with the second dose.
Interchangeability between vaccines
Regarding whether it is possible to obtain the first dose of a vaccine and the second from another vaccine, Dr. Swaminathan explained that the science is changing and developing and the knowledge base is growing, noting that there are currently clinical trials underway in some countries looking at the extent of interchangeability. Between the two doses of vaccines, which means that the first dose is from one of the vaccines, while the second dose is from a different vaccine, and maybe even a different vaccine platform.
The two doses of the same vaccine
Dr Swaminathan added: Immunologically, there are reasons that make this logical, but at the present time there is not enough data for the WHO to recommend this type of interchangeable dose schedule, therefore, for the time being, WHO recommendations remain, as Until the results of clinical trials are confirmed, the second dose of the same vaccine that was vaccinated in the first dose should be obtained.
The stages of developing and manufacturing the vaccine
Dr. Swaminathan answered a question by Vismita Gupta Smith about how to ensure that there are no long-term effects of these vaccines, especially since they were developed and manufactured at an unprecedented speed, saying that the development of the vaccine is a complex process that goes through different stages, from animal studies to experimental stages. Then comes the third and final stage of clinical trials in which tens of thousands of people are tested, half of whom receive a placebo and the other half receive the vaccine.
The volunteers’ cases are followed up over a period of time, usually lasting two years, and then the efficacy and safety of the vaccine is evaluated.
Emergency use to save lives
Dr Swaminathan added that due to the pandemic and the need to remove these vaccines quickly to save lives, the follow-up period was two months instead of years, and emergency use permits were granted for these vaccines, which means that they are still under observation and follow-up. And there are still follow-up and monitoring processes in different countries, which follow people who register and report any serious adverse reactions or uncommon reactions.
Update instructions always
In the same context, Dr. Swaminathan stated that the World Health Organization has a pharmacovigilance system, or a program to monitor and follow up the efficacy and safety of medicines and vaccines, which is applied to all agencies and vaccine manufacturers, and similar systems exist in many countries to monitor safety for the sake of continuous monitoring and vigilance of any Uncommon or emergency side effects, and then the reported cases are researched and analyzed to determine whether they are just an individual accident or are actually related to the vaccine itself. Dr Swaminathan confirmed that alerts or instructions are updated based on any developments.
150 million doses of vaccine
We know, and everyone also knows, that more than 150 million doses of vaccines have been given so far around the world, Dr. Swaminathan said, and the signals were extremely reassuring and confirmed the efficacy and safety of the vaccines, and no unwanted or unexpected symptoms appeared for the vaccines that were made. Ask it widely.
Continuous monitoring and great care
Dr. Swaminathan concluded her remarks by affirming the commitment of the World Health Organization, in cooperation with local authorities in each country, to continue monitoring and follow-up closely and very carefully, and if there is any evidence of a relationship between the vaccine and the side effect, this will be analyzed and the guidelines for countries updated from time to time.
#Urgent #questions #Corona #vaccine #dose #Phalanges