Vaccination only once against David-19, not enough

One of the problems is the distribution of the vaccine and supply of the countries. Other possible concerns involve obedience. Obeying people to take the vaccine not once but twice can be frightening to them.

There is no doubt that this will be the most complex program, the largest of vaccines in human history, and there will be another level of effort, sofistication, that we have never experienced before,” said Kelly Moore, doctor at Vanderbil University.

Two of the companies that are developing vaccines against Covid-19, Modernna and Pfizer, are now at the Faza 3 of clinical trials. 30,000 volunteers are receiving two doses from Modernna in a 28-day distance and Pfizer by 21 days.

AstraZeneca is expected to begin the Face 3 trials this month. Novavax has not yet begun Faza 3 tests, but has used two doses in their previous trials, abcnews writes. al

In the upcoming trials of Johnson & Johnson's phase 3, some participants will receive a dose and others will receive two doses. It is not surprising that people need to be vaccinated twice, as many Hepatitis A vaccines and Herpes é vaccines require two doses.

Some are looking for more children to get five doses of vaccine DTP, which protects them from diet, tetanosia and perfection.

It will be very difficult to convince Americans to vaccinate once, imagine twice. According to CNN's survey this month, 40% of Americans said they would not be vaccinated even if it was free.

Although there are people who want to be vaccinated, providing 660 million doses for 330 million Americans and convincing them to vaccinate twice seems like an impossible mission.