Grant M. Gallagher

An original version of this article was published on sister publication Contagion.

US Food and Drug Administration (FDA)-approved 

, according to investigators from the Rensselaer Polytechnic Institute (RPI).

SARS-CoV-2 uses its surface spike protein to bind to human cells. Heparin, a blood thinner also available in non-anticoagulant formulations, binds tightly with the coronavirus’ surface spike protein. A team led by Robert Linhardt, PhD, professor of chemistry and chemical biology at RPI, predicted that this tight binding might interfere with SARS-CoV-2 infection.

SARS-CoV-2 is particularly difficult for health systems to respond to; the virus presents a perfect storm of largely mild and asymptomatic transmission dynamics combined with the danger for very severe infection in a sizable minority of at-risk individuals.

Efforts to adapt to the unique virologic profile of SARS-CoV-2 have been greatly frustrated by the paucity of effective treatment and prevention options. In order to improve clinical outcomes, a variety of investigational therapies are being studied for use among patients with COVID-19. Specialty medications like remdesivir, favipiravir, and hydroxychloroquine have emerged from relative obscurity to garner intense media interest.  

The investigators speculated that heparin could be introduced into the body using a nasal spray or nebulizer in order to run interference on the coronavirus’ binding processes, lowering the odds of infection. “Decoy” strategies have been previously used against Zika virus, influenza A, and dengue.

"This approach could be used as an early intervention to reduce the infection among people who have tested positive, but aren't yet suffering symptoms. But we also see this as part of a larger antiviral strategy," Linhardt said. "Ultimately, we want a vaccine, but there are many ways to combat a virus, and as we've seen with HIV, with the right combination of therapies, we can control the disease until a vaccine is found."

Using a surface plasmon resonance direct binding assay, the study team discovered that SARS-CoV-2’s spike protein binds more tightly to immobilized heparin (KD = 40 pM VS 73 pM) than that of SARS-CoV and MERS-CoV (500 nM and 1 nM).

While the use of heparin as a COVID-19 treatment is currently theoretical, the study also serves a catalyst to further investigate the role of glycosaminoglycans in SARS-CoV-2 pathogenesis. Furthermore, the authors expressed hope that their findings provide a basis for further study of heparin-based interventions for COVID-19 patients exhibiting thrombotic complications.

"As soon as our labs reopen we are planning to begin animal studies on heparin administered to the nose and lung," Linhardt said.

Articles

New research shows the anticoagulant binds tightly with the coronavirus’ surface spike protein.

Heparin May Reduce SARS-CoV-2 Infection Risk

20vPnC Pneumococcal Conjugate Vaccine Candidate Shows Promise in Phase 3 Study

,” was originally published on ContagionLive.

Phase 3 trial results showed the immunogenicity and safety of a 20-valent 

 vaccine candidate (20vPnC), Pfizer Inc., has announced.

The study investigators found that safety objectives were met, and safety and tolerability were similar to licensed pneumococcal vaccines.

Investigators of the phase 3 randomized, double-blind trial enrolled 3880 participants to assess 20vPnC in adults 18 years of age and older who were not previously vaccinated against pneumococcal disease.

All serotypes in common with the licensed Prevnar 13 pneumococcal 13-valent conjugate vaccine met primary immunogenicity objectives of non-inferiority in adults 60 years of age and older at 1 month after vaccination.

Out of the 7 additional serotypes, when compared to the licensed PPSV23 pneumococcal polysaccharide vaccine, 6 met noninferiority objectives in adults 60 years of age and older.

“…1 of the new 7 serotypes missed noninferiority criteria by a small margin,” according to 

All 20 serotypes met noninferiority for secondary immunogenicity objectives comparing adults 18 to 59 with adults 60 to 64 years of age.

“The results from this pivotal study provide evidence that the 20vPnC vaccine is expected to have a comparable safety profile and likely be as effective as Prevnar 13 in helping prevent invasive pneumococcal disease and pneumonia due to the 13 serotypes in Prevnar 13, and also effective against disease due to the seven additional pneumococcal serotypes in adults 18 years of age or older,” Kathrin Jansen, PhD, head of vaccine research & development, at Pfizer, said in the statement.

In addition to the 13 serotypes included in Prevnar 13, 20vPnC includes 7 new serotypes which are associated with invasive pneumococcal disease cases with high fatality rates, antibiotic resistance, and/or meningitis. The 20 serotypes in 20vPnC are responsible for most circulating pneumococcal disease globally.

“This is particularly important for the 7 additional pneumococcal serotypes due to the burden of pneumonia caused by the new serotypes and the lack of herd protection for adults since the current pediatric vaccine does not protect against the seven additional strains,” Luis Jodar, PhD, chief medical and scientific affairs officer for Pfizer Vaccines said in the statement.

The 20vPnC vaccine candidate was granted Breakthrough Therapy Designation by the US Food and Drug Administration (FDA) in 2018.

The vaccine candidate was also granted Fast Track designations for adults and pediatric populations in 2017.

There are 2 additional trials of 20vPnC completed, with results expected within the coming months.

Of the additional trials, 1 was a randomized double-blind trial meant to provide additional safety data and evaluate 3 different lots of 20vPnC in adults between 18 through 49 years of age without a history of pneumococcal vaccination.

The other additional study was an open label, randomized trial providing data on the safety and immune response of 20vPnC in about 875 adults 65 years of age and older who have a prior history of pneumococcal vaccination.

Pneumococcal and other vaccines are linked to considerable 

 in childhood mortality from lower-respiratory infections over the past 3 decades.

In general, pneumococcal vaccines have led to reduction in not only pneumonia, but also sepsis and bacteremia in immunized populations. However, there are 

 that the current vaccine strategy does not adequately address meningitis, making expansion of the vaccine arsenal an important goal.

The vaccine is safe and effective in preventing pneumococcal disease and pneumonia.