Since there are four distinct dengue viruses, the challenge is to concoct a four-way, or "tetravalent," vaccine, effective against all strains at once.    From Wordnik.com.  [The Bug Is Back] Reference

The new vaccine is tetravalent, meaning that it is designed to protect against all four dengue viruses, also called serotypes.    From Wordnik.com.  [PhysOrg.com - latest science and technology news stories] Reference

Every node in this graph was tetravalent: connected by four edges to four other nodes.    From Wordnik.com.  [In the beginning] Reference

Finally one atom of a tetravalent element such as carbon will combine with four atoms of a univalent element, as in the compound.    From Wordnik.com.  [An Elementary Study of Chemistry] Reference

Clinical studies with its most advanced tetravalent candidate vaccine started in the 2000s.    From Wordnik.com.  [The Earth Times Online Newspaper] Reference

"If the pentavalent vaccine is re-introduced, the tetravalent vaccine will be withdrawn," he said.    From Wordnik.com.  [Kuensel Newspaper] Reference

"The tetravalent vaccine we have in stock will last for only about three months," Dr Ugen Dophu added.    From Wordnik.com.  [Kuensel Newspaper] Reference

Two Zn2+ ions (A and C) are involved in tetravalent coordination with residues from the two independent crystallographic Fabs.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

In this Phase I trial, study volunteers who have never been exposed to dengue were randomly assigned to receive one of the candidate tetravalent vaccine formulations or a placebo.    From Wordnik.com.  [PhysOrg.com - latest science and technology news stories] Reference

After determining which tetravalent vaccine is most promising, the researchers will test that candidate in a trial in a new group of volunteers in Brazil, where dengue has become highly prevalent.    From Wordnik.com.  [PhysOrg.com - latest science and technology news stories] Reference

Unlike before, where it was said that parents would be given a choice between the tetravalent vaccine and the pentavalent vaccine, Dr Ugen Dophu said that only one of them would be in the immunisation schedule.    From Wordnik.com.  [Kuensel Newspaper] Reference

"Our overall strategy was to identify the best individual candidate for each serotype, based on safety and ability to induce an immune response, and to then combine those into a tetravalent vaccine," explains Dr. Whitehead.    From Wordnik.com.  [PhysOrg.com - latest science and technology news stories] Reference

Firstly, protein interface zinc-binding sites are formed between the Fab1 and Fab2 molecules and involve the tetravalent coordination by Fab residues (.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference