Since the beginning of the Covid-19 pandemic, the world has been looking for a viable alternative to control infections and eradicate the deadly disease that has claimed millions of lives in more than a year.
Physical distance and masks helped, but it was not palliative enough.
The challenge for science is to reduce infections and fight this coronavirus through vaccines, which several countries have already begun administering, and the Dominican Republic does not yet have a specific start date, although the government has said it will announce the plan on Monday, February 15. vaccination.
As of December 2020, there were over 200 candidate vaccines under development, of which 7 are already circulating in the world, although they are used in case of emergency.
The Dominican Republic will receive vaccines from Pfizer, AstraZeneca and Sinovac, the latter was announced by President Luis Abinader on Thursday. How effective are these vaccinations?
Pfizer-BioNTech
The BNT162b2 vaccine from Pfizer and BioNTech is 95% effective, being the highest percentage of over 30 vaccines in the world.
Clinical trials have now completed phase 3 and are recommended for use in persons 16 years of age or older. However, its application is not recommended for people who have reacted with allergies to polyethylene glycol (PEG) and polysorbate.
Although two doses are required, 21 days apart, if the patient has had a severe or immediate allergic reaction to the first dose, they should not receive a second injection.
It must be refrigerated at -70º and can remain frozen for five days.
Its use is authorized by the United States, the United Kingdom, the European Union, the World Health Organization and other countries.
Chills, fatigue and headaches are some of the side effects that occur within 7 days of vaccination.
With this pharmaceutical company, the Dominican government has signed a mid-term agreement to provide 7.9 million doses of BNT162b2 vaccine.
The agreement was signed by the Minister of Public Health, Dr. Plutarco Arias, representing the Dominican Republic.
Prior to the deal, President Luis Abinader reported on Friday, January 8, that he expected to receive about 25,000 doses of the vaccine manufactured by the pharmaceutical company Pfizer during that month, but this delivery was not made. .
Pfizer and other pharmaceutical companies have had delays in delivering vaccines to contracted countries.
Modern (United States)
With 94.1% efficacy and phase 3 clinical trials completed, the vaccine developed by the pharmaceutical company Moderna is the second most effective of those announced in the world, as well as the second to be approved by the European Medicines Agency (EMA). ).
This vaccine requires storage for 30 days, but can withstand up to six months refrigerated at -20 degrees Celsius.
For its effective use, two applications must be made with a difference of 28 days between each. However, in late January, the pharmaceutical company announced that the effectiveness of generating antibodies against the South African version is lower than for the original virus, so it is working on a new vaccine that can be added to the current treatment of the two doses. .
The United States, Canada, the United Kingdom, Israel, Switzerland and the countries that make up the European Union are some of those already applying the Moderna vaccine, developed in conjunction with the US National Institutes of Health and authorized by the World Health Organization. Health.
In addition, the US Food and Drug Administration (FDA) has authorized the covid-19 Moderna vaccine for emergency use in that country.
Sputnik V
The Russian vaccine Sputnik V, developed by the Gamaleya Research Institute in Russia, is one of three vaccines in the world with an efficacy of more than 90%.
Like those produced by Johnson & Johnson and AstraZeneca, Sputnik V is a viral vector, as opposed to using a different adenovirus at each dose.
According to Gamaleya research, the efficacy against Covid-19 of this vaccine named after the first Soviet space satellite is 91.6%, after demonstrating high immunogenicity and safety during phase III clinical trials.
Contrary to what experts believe about AstraZeneca, the research center says that the effectiveness of the vaccine for the elderly was 91.8% and did not differ statistically from that of the group of people aged between 18 and 60 years.
This vaccine requires two doses, three weeks apart.
“To ensure long-term immunity, Russian scientists have developed the new idea of using two different types of adenoviral vectors (rAd26 and rAd5) for the first and second dose of vaccine, thus strengthening its immunizing effect,” he explains. vaccine site page.
As for storage, it must be refrigerated at -20 degrees Celsius.
Sputnik V has been registered in about 15 countries, including Russia, Venezuela, Argentina, Bolivia, Belarus, Serbia and Algeria.
Oxford-AstraZeneca
The Dominican Republic and the Anglo-Swedish company AstraZeneca have signed a contract to purchase 10 million doses of vaccine against Covid-19.
The technology used in AstraZeneca vaccines is a viral vector, meaning a harmless virus is created to contain the SARS-CoV-2 peak protein gene, which prepares the immune system to attack the SARS-CoV-2 virus. then it infects the body.
The drug manufacturer reported an efficacy of over 70%. However, according to EMA data, approximately 60% efficacy has been demonstrated in clinical trials.
Currently, the Covid-19 AstraZeneca vaccine is not recommended for use in children; While in adults over the age of 55, WHO experts have recently expressed distrust of the efficacy in the elderly and against the South African variant of the virus.
Developed in conjunction with Oxford University, the AstraZeneca application is licensed in nearly 50 countries, including the United Kingdom, India, Morocco, the European Union and several Latin American countries.
For storage, the vaccine must be refrigerated at a temperature of 2 to 8 degrees Celsius for at least six months.
Sinopharm
The technology of this vaccine consists of the inactivated virus. The SARS-CoV-2 virus is rendered inert by a process that preserves the structure of the virus and is subsequently unable to reproduce, but generates an immune response in the body.
Developed by the Chinese state pharmaceutical company Sinopharm and the Beijing Institute of Biological Products, the vaccine has completed the last phase of clinical trials and has an efficacy rate of 79%. The lab sought regulatory approval for the injection, approaching China’s first vaccine approved for use by the general public.
Its use is authorized in China and other countries, such as Hungary, Serbia, the United Arab Emirates, Bahrain, the Seychelles, Egypt, Laos and Morocco. The required doses are two to three weeks apart.
Like AstraZeneca, storage is 2 to 8 degrees Celsius.
Johnson & Johnson
Johnson & Johnson is a well-known company in the country for the baby care products they distribute, but they are also manufacturers of medical devices and pharmaceuticals, one of the most recent being a vaccine against Covid-19.
The technology used is the viral vector, as are AstraZeneca and Sputnik V.
According to journalistic reports, the vaccine has shown an effectiveness of 66% at a rate of 85% when it comes to preventing serious images of the disease.
But the breakdown of the data showed that the tests were more effective in the United States (72%) than in South Africa (57%), where there is a different strain of virus that is predominant.
The company applied to the FDA for the use of this vaccine, to which the company informed that it will issue its opinion at the end of February after studying the data from the clinical trials.
Some advantages of this medicine are that it is a single dose and does not require storage in special freezers. In addition, it can remain frozen for two years at -20 degrees Celsius and three months in the refrigerator between 2 and 8 degrees Celsius.
CoronaVac
CoronaVac is a vaccine against COVID-19 developed by the Chinese pharmaceutical company Sinovac Biotech, a developer specializing in vaccines, including for hepatitis A and B, seasonal flu, swine flu and bird flu.
The effectiveness of this inoculation, according to Sinovac, is about 50% in the prevention of infections and 80% in cases that require hospitalization. These data resulted from clinical trials and tests performed in Brazil and Indonesia during phase 3.
Coronavac became the second coronavirus vaccine approved by China in early February and is used in Indonesia, Brazil and Turkey.
According to France24, CoronaVac needs two doses to be effective and requires a standard refrigeration between 2 and 8 degrees Celsius.
On Thursday afternoon, President Luis Abinader announced the purchase of 768,000 new vaccines from Sinovac.
The president did not specify how much the Dominican Republic would cost.
Unknown efficacy
Other developing vaccines include CureVac (Germany / USA) of RNA messenger and Novavax, developed in the United States with top recombinant proteins, but the efficacy of both is unknown.
Although the American pharmaceutical drug Novavax reported in late January that during clinical trials they achieved an efficacy of 89.6% for the virus variant found in the United Kingdom.
Similarly, there is inoculation Sanofi / GSK (France and the United Kingdom), developed with recombinant proteins. It was reported in early February that after a disappointing phase 2 trial, companies are testing another form of antigen and are now targeting production later this year.
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Other vaccines
In addition to the above, there are other vaccines, such as those of the Indian company Bharat Biotech, developed and licensed in their country of origin, whose phase 3 clinical trials have not been completed. These are Covishield and Covaxin.
MRNA technology
The two most effective vaccines according to the competent organizations and entities have in common their development achieved with messenger RNA (mRNA) technology.
This form is that the drug teaches our cells to produce a protein that triggers an immune response in our body.
On its website, the Centers for Disease Control and Prevention (CDC) explains that this immune response, which produces antibodies, is what protects us from infections if the real virus enters our body.
It should be noted that these vaccines cannot cause COVID-19 and do not contain the live virus that causes COVID-19. Likewise, they do not affect our DNA and do not interact with it in any way.