As with other studies in which chimpanzees are used for infectious disease research, there is a disparity between the human and chimpanzee course of RSV infection – putting the value of this research into question.

RSV research requires that very young chimpanzees be separated from their mothers when they are very young.

Information on RSV studies at private biomedical companies is unavailable.

About RSV

In humans, RSV typically does not cause serious illness, and its symptoms may go unnoticed. It is estimated that by age three, most children have been infected at some time with RSV. (1)

Typical symptoms mimic the common cold and may progress to coughing and/or wheezing. Serious illness can result, usually in immunocompromised populations such as the elderly, infants who were born prematurely, and young children suffering from respiratory or cardiac disorders. (2)

RSV is most prevalent during the fall and winter months. Most RSV infections do not require treatment, but for those that do, treatments typically consists of relieving the symptoms of upper and lower respiratory congestion and cough. For serious infections requiring hospitalization, antiviral treatments such as Ribavirin (3) and intravenous immune globulin may be administered. (4)

A range of human clinical studies are currently funded by the National Institutes of Health (NIH) to study treatment of RSV. In 2004, NIH funded 26 human clinical studies of RSV. (5) (This number does not include any prior studies which may still have been in progress during this time.)

The use of chimpanzee infants in RSV research

As with other studies in which chimpanzees are used for infectious disease research, there are significant differences between the human and chimpanzee course of infection from RSV. RSV infection in chimpanzees causes them to experience a moderate nasal discharge similar to the common cold. There does not appear to be any further progression of the disease in chimpanzees. (6)

Overall young chimpanzees appear to be less susceptible to the replication and pathology of RSV infection. (7) RSV does not appear to cause illness beyond mild to moderate nasal congestion, and chimpanzees appear to develop a natural immunity to the virus by the age of two. (8)

Chimpanzees used in RSV research must be less than two years old because after that time they develop protective antibodies to RSV infection. (9) This greatly increases the emotional toll on chimpanzees used for RSV research. A young chimpanzee is typically not weaned before the age of five and in nature is almost constantly by his or her mother’s side during those first years of life.

In addition to the severe distress caused by separation from their mothers (and stress to the mothers themselves), experimental procedures required for RSV entail collecting:

nasopharyngeal swabs and tracheal lavage [irrigation] samples … at intervals over 10 days …(10)

Tracheal lavage must be carried out under general anesthesia, as is the initial procedure of infecting the young chimpanzees with intranasal and intratracheal inoculation of the virus.

Overview of recent federally funded studies using chimpanzees for RSV
(As noted above, there are no current government funded studies.)

From the abstract: In chimpanzees, the replication of the wt AB chimera was intermediate between that of the A2 and B1 wt viruses, and was accompanied by moderate rhinorrhea, [nasal discharge] as previously seen in this species.

(The individuals in this study are housed at BIOQUAL, Inc.) (12)

Last update: 1/11/06

Sources

(1) Babies Today. RSV: Battling the wintertime bug. http://babiestoday.com/resources/articles/rsv.htm

(2) The RSV Info Center. Web retrieved at http://www.rsvinfo.com/sequelae/sequelae.html

(3) Krilov, LR. Respiratory Syncytial Virus, EMedicine, web retrieved October 2005 at http://www.emedicine.com/PED/topic2706.htm

(4) Center for Disease Control, Respiratory and Enteric Diseases Branch http://www.cdc.gov/ncidod/dvrd/revb/respiratory/rsvfeat.htm

(5) Computer Retrieval of Information on Scientific Projects (CRISP), http://crisp.cit.nih.gov/

(6) Whitehead SS, Hill MG, et al. 1999. Replacement of the F and G proteins of respiratory syncytial virus (RSV) subgroup A with those of subgroup B generates chimeric live attenuated RSV subgroup B vaccine candidates. J Virol. Dec;73(12):9773-80.

(7) Teng MN, Whitehead SS et al. 2000. Recombinant Respiratory Syncytial Virus That Does Not Express the NS1 or M2-2 Protein Is Highly Attenuated and Immunogenic in Chimpanzees. J Virol. October; 74(19): p. 9320

(8) Sibal, LR and Samson, KJ. 2001. Nonhuman Primates: A Critical Role in Current Disease Research, ILAR Journal V42(2):78.

(9) Sibal, LR and Samson, KJ. 2001. Nonhuman Primates: A Critical Role in Current Disease Research, ILAR Journal V42(2):78.

(10) Teng MN, Whitehead SS et al. 2000. Recombinant Respiratory Syncytial Virus That Does Not Express the NS1 or M2-2 Protein Is Highly Attenuated and Immunogenic in Chimpanzees. J Virol. October; 74(19):9318

(11) Funding amounts and length of studies are not available for studies conducted at NIH laboratories or any of its divisions. (referred to as intramural research).

(12) Whitehead SS, Hill MG, et al. 1999. Replacement of the F and G proteins of respiratory syncytial virus (RSV) subgroup A with those of subgroup B generates chimeric live attenuated RSV subgroup B vaccine candidates. J Virol. Dec;73(12):9773-80.

^ back to top