Should we get our vaccines against Pneumonia?

Pneumonia is a parenchymal infection of the lungs that presents with acute or subacute onset of fever, productive cough, pleuritic chest pain, localized râles, and radiological signs of consolidation. There are three categories of this disease:

  1. Community-acquired pneumonia (CAP)
  2. Healthcare- associated pneumonia (HCAP)
  3. Nosocomial pneumonia.

It is a worldwide leading cause of emergency visits, hospitalizations, and death; according to the World Health Organization (WHO) it is the fourth leading cause of death, killing more than 2.6 million lives I 2019. There are two major peaks of incidence:

  1. Children less than 5 years of age.
  2. Adults older than 75 years of age.

The combined mortality for influenza and pneumonia has radically decreased in the USA—from 23.7 per 100,000 inhabitants in 2000 to 15.2 per 100,000 inhabitants in 2019—due to the falling of smoking rates across all socio-economic segments of the American population and the increase of use of the corresponding vaccines. According to the American Public Health authorities, the best strategy to decrease the morbidity and mortality rates of CAP is to vaccinate the target groups:

  1. Age: individuals less than 5 years of age and older than 65 years old.
  2. Smoking history.
  3. Chronic Lung diseases: Chronic Obstructive Pulmonary Disease (COPD) Childhood Pneumonia, Occupational dust exposure.

The best strategy to decrease the morbidity and mortality of HCAP is to:

  1. Maintain critical pulmonary defense mechanisms.
  2. Reduce the incidence of intra-hospital infections and similar care events.

The most common pathogen producing Pneumonia is Staphylococcus Pneumoniae, which has been identified in almost a third of patients that had proper testing and approximately 40-50% of all blood cultures-confirmed cases. Patients with COPD often have tracheobronchial colonization with a mix of S. Pneumoniae, Hemophilus Influenzae and Mycoplasma catarrhalis. Heavy use of alcohol carries the risk of dangerous pathogens like anaerobic bacteria, which predispose to lung abscess and empyema, and the opportunistic emergence of gram-negative bacilli tougher to treat.

The American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA) noted in their 2005 guidelines that the three variants of pneumonia associated with healthcare facilities –HAP, VAP and HCAP— “are similar in that they often result from colonization, then infection by resistant gram-negative bacilli and methicillin-resistant Staphylococcus aureus (MRSA) necessitating broader empiric antibiotic therapy than that commonly used for CAP.”  These same ATS/IDSA guidelines do not recommend the routine use of blood cultures in the ambulatory setting, except in the following circumstances:

  1. Symptoms or signs of severe CAP.
  2. Suspicion of drug resistant or rare pathogens.
  3. No response to empiric antibiotic treatment after 72 hours.

The same ATS/IDSA guidelines recommend the pre-treatment use of blood cultures before initiating treatment in hospitalized patients who are classified as severe CAP, are being empirically treated for MRSA or gram-negative bacilli or have one of the following: a) cavitary infiltrates, b) leukopenia, c) chronic alcoholism, d) chronic liver disease, e) COPD, f) pleural effusion, g) no spleen, and h) admission to ICU.

Patients who do not have any life-threatening conditions can be managed at home. Pending the results of any blood cultures that were obtained, the 2019 ATS/IDSA guidelines recommend the following initial treatment for Pneumonia:

  1. Amoxicillin 1 gram three times per day.
  2. Doxycycline 100 mg twice per day.
  3. Or a macrolide monotherapy—azithromycin 500 mg on first day and then 250mg per day or clarithromycin 500 mg twice per day.

The ATS/IDSA guidelines recommend at least five (5) days of antibiotic treatment which should be extended 48 to t72 hours if there were any complications; when gram negative or Staphylococcus bacteria are present, treatment should be longer as these pathogens tend to destroy pulmonary tissue and provoke residual scarring.

Note. This 1802 caricature of the Anti-Vaccination movement by Edward Gillray was taken from Wikimedia Commons.

As it has happened ever since Edward Jenner introduced the life saving vaccines against smallpox, there are detractors of the Pneumococcal vaccination. What does the science say?

Pneumococcal vaccination has significantly improved over the past few years, as more variants are accounted for. A single agent, PPSV23, had been traditionally used for immunocompromised individuals and those older than 65 years; it is effective against 85 to 90% of the pneumococcal serotypes in our communities. Considering that the polysaccharide vaccines are not effective in children less than 2 or 3 years of age, we must use conjugate vaccines. In 2010 a 13-valent conjugate vaccine dubbed as PCV13was introduced in the market and its use has steadily decrease the incidence of the disease in children. In 2013 that vaccine was recommended for immunocompromised individuals and two years later for adults older than 65 years. However, considering the sharp decline of Pneumococcal infections in adults after he introduction of PCV 13 in children, they amended that recommendation already.

The influenza vaccine is a trivalent live vaccine that contains the three virus variants that are expected to be prevalent the year following its manufacture. Combined with the pneumococcal vaccine, it has been effective in reducing flu and pneumonia in the USA. However, their use is still limited due to poorly designed Public Health initiatives and lack of provider effective participation in vaccination campaigns.

A September 2022 communique of the CDC to physicians says: “The 13-valent pneumococcal conjugate (PCV15 from Wyeth Pharmaceuticals) and the 23-valent pneumococcal  polysaccharide vaccine (PPSV23 from Merck, Sharp and Dohme) has been recommended for American children; those recommnendations vary by age group and risk groups.”

We, physicians, are notorious for missing that needed vaccination again and again. We paradoxically scold our patients for not getting their yearly flu shots, but….We never got one ourselves. We solemnly promise to get our flu and pneumococcal shots after we get the bivalent Pfizer Covid booster and the Holidays passed. Why? Because we want to minimize any risk, no matter how small it might be,  of interference with the plentiful food and drinks we are planning to load our bodies with. Hey. give us a break…We’re only human!!!

Stay distant. Stay safe. Stay beautiful.

What do you think? Please tell us.

Don’t leave me alone.