The drugs Molnupiravir and Paxlovid are a tool, a complement to treat COVID-19, which should not replace vaccination, nor should they be considered as a cure by themselves, agreed experts, Carlos Arias Ortiz, and Alejandro Sanchez Flores, from UNAM's Institute of Biotechnology.

The new drugs, specified Arias Ortiz, are a treatment for people who have been diagnosed and are at risk of severe disease or death "they are not drugs that cure, but they prevent the severity of the disease and also death". The available data we have available indicates that the possibility of death is very low if they are taken.

In turn, Sanchez Flores commented: "having these treatments gives us one more tool to fight the disease. We know that despite having vaccines that prevent serious symptoms and death, some cases get out of control. There is always a percentage in which the vaccine does not generate the immune response that is expected and having access to the drug, especially at the onset of symptoms, gives us the option of being able to reduce the cases of serious diseases... it is a compliment that should not replace vaccination.

Molnupiravir, from the US pharmaceutical company Merck, received authorization in the United Kingdom and also approval for emergency use from the EMA (European Medicines Agency) as a treatment against COVID-19, and the same response is expected from the FDA in the United States; meanwhile, Paxlovid, also from the US company Pfizer, requested authorization from the US regulatory body on November 9.

The two drugs will be an additional strategy that will reduce deaths in those cases that require it, but according to Carlos Arias, it is not recommended for all people who contract COVID-19, but only for those who are older and have comorbidities; that is to say, a risk of suffering a severe disease or death. Therefore, it is not thought to be prescribed for young people, particularly for those who do not present disorders.

How effective are they?

It is important to know that the clinical trials of both drugs are not published or peer-reviewed, so only the statements of the companies that developed them are available, Arias Ortiz pointed out.

"In the case of Molnupiravir, 7 percent of the patients treated with the drug were hospitalized, compared to 14 percent of the group of those who did not take it. On the other hand, during the study no people who had received the drug died, while in the group that was given a placebo there were eight deaths, so it has 100 percent protection against death and 50 percent effectiveness against severe disease.

"In the case of Paxlovid, what they found was that 0.8 percent of those in the study had to be hospitalized, versus 7 percent in the placebo group; this implies 89 percent effectiveness against hospitalization. And against death, 100 percent effectiveness was reported, versus seven deaths among those who received the placebo," said Carlos Arias.

The trials were so effective that they were suspended for ethical reasons since it is not right to continue giving placebos to people with comorbidities when they can be given the treatment.

For Alejandro Sanchez, "the drugs will help to avoid serious symptoms and death. Just as vaccines do, but so that at the end of the day that number that falls outside the percentage of efficacy can be treated with pills. If we think about it a little bit, this gives a much smaller bottleneck because production would not be so massive. That would give a cost reduction. But drugs are not a substitute, people should be clear about that. It is a complement, an extra lifeline.

When will they be available?

Carlos Arias Ortiz stated: "it is difficult to say when they will be available, but what the companies have said is that Merck will have 10 million treatments by the end of the year, of which the United States has already purchased 1.7 million; in the case of Pfizer they will have about 100,000 treatments, according to their statements. They are few. It also depends on next year's production capacity, on-demand and on the speed with which these products can be licensed to India, in particular, but it will hardly be available in Mexico next year".

One of the advantages that Molnupiravir has is that it has an open patent; that is, it can be licensed to be produced in other nations by more companies, in a generic way, which could lower costs.

"There is a United Nations backing known as the Medicines Patent Fund, which negotiates with the companies that have the patent to license it to low-income and middle-income countries for generic production. This will allow, according to Merck, 105 nations to have the opportunity to produce this drug in their facilities, at least those that have the capacity. Importantly, it has already been licensed to eight companies in India, and surely through these companies and those who can produce it, costs can be lowered. Even so, it may take time for it to become available due to the demand from rich countries. The drug is restricted to be administered to SARS-CoV-2 positive people who are in the first days of symptoms and who are at risk due to comorbidities," he explained.

How much do they cost?

Molnupiravir has an approximate cost of 700 dollars, that is, 14 thousand Mexican pesos, according to the company's statement. Pfizer has not announced a price for Paxlovid; however, it indicated that it will try to make it affordable for middle-income countries, in addition to licenses for manufacturing in nations that have the capacity, thus reducing costs. Both researchers agreed that the measures aimed at mitigating the number of infections should be maintained: use of masks, healthy distance, and, mainly, vaccination.

"The problem is that it will take many years, at least two, for us to have a homogeneous vaccination, especially due to the appearance of the Delta variant, which is expected to be the predominant one in the world. Possibly it will become endemic and this means that we are going to see it circulating, but the variations it is suffering are sub-lineages of the Delta, they have characteristics of greater transmission but there could be an attenuation, either because the vaccination percentage will be very high or because we finally find a balance between the virus and us, in which the virus is transmitted but does not cause such serious symptoms", concluded Sanchez Flores.