The strategy against COVID-19 involves vaccination, personal protection measures (such as wearing face masks, ventilation, hand washing and safety distancing) and epidemiological control of cases and contacts. Not only in developed countries, but worldwide. The pandemic is not over yet, so we are asking our GP, Dr. Celedonio Perea Marcos, some questions related to the pandemic.

How long does the vaccine can protect us for, for 6 months or for a year?

The vaccine currently provides only partial immunity and is not “sterilising”, and the infection is possible, although somewhat less likely with the same exposure, and transmission as well. It is not known how long it protects for exactly, but it is known that the level of antibodies decreases over time. Despite that, cell-based immunity persists.

Should everyone get revaccinated, or only those who no longer have antibodies?

The amount of antibodies in blood is not the determining factor. The need for the third dose of the vaccine is primarily advised to those who belong in the following risk groups:

  • Those older than 70 years of age, provided that six months have passed since the vaccination was completed. Later it will be extended to other age groups.
  • Health and social health staff members.
  • Population vaccinated with the Janssen single dose.
  • Patients with solid organ transplants and hematopoietic stem cell transplant (HSCT).
  • People on anti-CD20 drugs.
  • Oncohematological disease and solid organ cancers.
  • All primary immunodeficiencies, excluding IgA deficiency and antibody production defect.
  • Very high risk patients on certain immunosuppressive treatment.
  • People with renal replacement therapy (hemodialysis and peritoneal dialysis).
  • Cystic fibrosis.
  • Down syndrome with 40 or more years of age.
  • People residing in retirement homes, given their profile of frailty, multiple pathologies and closed environments.

Why is the number of cases rising if the majority of the population is already vaccinated?

The vaccine protects against becoming seriously ill or dying from COVID-19, greatly affecting the morbidity and mortality rates of the disease, and only slightly affecting the transmission rate. That means personal protection measures remain crucial, and further restrictions may become necessary. Personal protection measures are currently being relaxed in Spain. Correct epidemiological control of cases and contacts during the pandemic is also essential (easier to do when the incidence is low).

What do we know about Pfizer COVID-19 medicine?

The pharmaceutical company Pfizer has obtained an experimental drug designed to prevent the virus from making copies of itself and invading the infected organism, representing a very promising step in treating the coronavirus, as it is capable of reducing the risk of hospitalisation and death by almost 90% among those who got infected.

In line with the new Omicron variant, which has just been detected in South Africa, it must be said that we still cannot know the extent of its severity, and that it is very important that vaccination advances worldwide, together with personal protection measures and community epidemiological control, because it is the only way to prevent potentially more dangerous new variants.