US biopharmaceutical companies are currently developing 271 vaccines to prevent - and, in some cases, treat - a variety of conditions, including infectious diseases, various forms of cancer and neurological disorders, according to a new report.

All of the 271 potential vaccines are currently in human clinical trials or under review at the Food and Drug Administration (FDA), according to the study, which has been published by the Pharmaceutical Research and Manufacturers of America (PhRMA).

The products include 137 potential new vaccines against infectious diseases, 99 against cancer, 15 for allergies, 10 for neurological disorders and 13 others, it notes.

The report highlights details of a number of the products now in development, including: 

- for malaria, an irradiated vaccine which has been shown in early clinical trials to be 100% effective in preventing the transmission of the disease from infected mosquitoes to humans;

- cervical cancer: a live, attenuated Listeria monocytogenes (LM)-based immunotherapy for the treatment of women who already have cervical cancer as a result of infection by the human papillomavirus (HPV);

- HIV: a therapeutic vaccine which is targeting the low-mutating (conserved) parts from the protein p24 of the HIV virus. The vaccine consists of four peptides that are modified to increase the immune response against the conserved parts of the p24 protein - a sustained immune response against the p24 protein has been shown to be associated with delayed disease progression;

- flu: a monoclonal antibody (mAb) vaccine which targets both pandemic and severe seasonal influenza A virus infections;

- pancreatic cancer: a combination of a Listeria-based vaccine that has been engineered to express the tumour-associated antigen mesothelin and allogeneic pancreatic cancer cells that are genetically-modified to secrete the immune-stimulant granulocyte-macrophage colony stimulating factor (GM-CSF). Sequential administration of the vaccines in animal studies has demonstrated enhanced tumour-specific T-cell and anti-tumour responses; and

- smoking cessation: one of a new class of targeted vaccines induces an antigen-specific immune activation for smoking cessation and relapse prevention. The vaccine is made from biocompatible and biodegradable materials and is a full synthetic nanoparticle vaccine engineered to mimic the properties of natural pathogens to elicit an immune response.

The study also reports that there are currently 204 active clinical trials for vaccines in the US. They include 107 which have not yet started recruiting patients or which are just now seeking volunteers to participate.